Category Archives: military

Suit up with nanofiber for protection against explosions and high temperatures

Where explosions are concerned you might expect to see some army research and you would be right. A June 29, 2020 news item on ScienceDaily breaks the news,

Since World War I, the vast majority of American combat casualties has come not from gunshot wounds but from explosions. Today, most soldiers wear a heavy, bullet-proof vest to protect their torso but much of their body remains exposed to the indiscriminate aim of explosive fragments and shrapnel.

Designing equipment to protect extremities against the extreme temperatures and deadly projectiles that accompany an explosion has been difficult because of a fundamental property of materials. Materials that are strong enough to protect against ballistic threats can’t protect against extreme temperatures and vice versa. As a result, much of today’s protective equipment is composed of multiple layers of different materials, leading to bulky, heavy gear that, if worn on the arms and legs, would severely limit a soldier’s mobility.

Now, Harvard University researchers, in collaboration with the U.S. Army Combat Capabilities Development Command Soldier Center (CCDC SC) and West Point, have developed a lightweight, multifunctional nanofiber material that can protect wearers from both extreme temperatures and ballistic threats.

A June 29, 2020 Harvard University news release (also on EurekAlert) by Leah Burrows, which originated the news item, expands on the theme,

“When I was in combat in Afghanistan, I saw firsthand how body armor could save lives,” said senior author Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and a lieutenant colonel in the United States Army Reserve. “I also saw how heavy body armor could limit mobility. As soldiers on the battlefield, the three primary tasks are to move, shoot, and communicate. If you limit one of those, you decrease survivability and you endanger mission success.”

“Our goal was to design a multifunctional material that could protect someone working in an extreme environment, such as an astronaut, firefighter or soldier, from the many different threats they face,” said Grant M. Gonzalez, a postdoctoral fellow at SEAS and first author of the paper.

In order to achieve this practical goal, the researchers needed to explore the tradeoff between mechanical protection and thermal insulation, properties rooted in a material’s molecular structure and orientation.

Materials with strong mechanical protection, such as metals and ceramics, have a highly ordered and aligned molecular structure. This structure allows them to withstand and distribute the energy of a direct blow. Insulating materials, on the other hand, have a much less ordered structure, which prevents the transmission of heat through the material.

Kevlar and Twaron are commercial products used extensively in protective equipment and can provide either ballistic or thermal protection, depending on how they are manufactured. Woven Kevlar, for example, has a highly aligned crystalline structure and is used in protective bulletproof vests. Porous Kevlar aerogels, on the other hand, have been shown to have high thermal insulation.

“Our idea was to use this Kevlar polymer to combine the woven, ordered structure of fibers with the porosity of aerogels to make long, continuous fibers with porous spacing in between,” said Gonzalez. “In this system, the long fibers could resist a mechanical impact while the pores would limit heat diffusion.”

The research team used immersion Rotary Jet-Spinning (iRJS), a technique developed by Parker’s Disease Biophysics Group, to manufacture the fibers. In this technique, a liquid polymer solution is loaded into a reservoir and pushed out through a tiny opening by centrifugal force as the device spins. When the polymer solution shoots out of the reservoir, it first passes through an area of open air, where the polymers elongate and the chains align. Then the solution hits a liquid bath that removes the solvent and precipitates the polymers to form solid fibers. Since the bath is also spinning — like water in a salad spinner — the nanofibers follow the stream of the vortex and wrap around a rotating collector at the base of the device.

By tuning the viscosity of the liquid polymer solution, the researchers were able to spin long, aligned nanofibers into porous sheets — providing enough order to protect against projectiles but enough disorder to protect against heat. In about 10 minutes, the team could spin sheets about 10 by 30 centimeters in size.

To test the sheets, the Harvard team turned to their collaborators to perform ballistic tests. Researchers at CCDC SC in Natick, Massachusetts simulated shrapnel impact by shooting large, BB-like projectiles at the sample. The team performed tests by sandwiching the nanofiber sheets between sheets of woven Twaron. They observed little difference in protection between a stack of all woven Twaron sheets and a combined stack of woven Twaron and spun nanofibers.

“The capabilities of the CCDC SC allow us to quantify the successes of our fibers from the perspective of protective equipment for warfighters, specifically,” said Gonzalez.

“Academic collaborations, especially those with distinguished local universities such as Harvard, provide CCDC SC the opportunity to leverage cutting-edge expertise and facilities to augment our own R&D capabilities,” said Kathleen Swana, a researcher at CCDC SC and one of the paper’s authors. “CCDC SC, in return, provides valuable scientific and soldier-centric expertise and testing capabilities to help drive the research forward.”

In testing for thermal protection, the researchers found that the nanofibers provided 20 times the heat insulation capability of commercial Twaron and Kevlar.

“While there are improvements that could be made, we have pushed the boundaries of what’s possible and started moving the field towards this kind of multifunctional material,” said Gonzalez.

“We’ve shown that you can develop highly protective textiles for people that work in harm’s way,” said Parker. “Our challenge now is to evolve the scientific advances to innovative products for my brothers and sisters in arms.”

Harvard’s Office of Technology Development has filed a patent application for the technology and is actively seeking commercialization opportunities.

Here’s a link to and a citation for the paper,

para-Aramid Fiber Sheets for Simultaneous Mechanical and Thermal Protection in Extreme Environments by Grant M. Gonzalez, Janet Ward, John Song, Kathleen Swana, Stephen A. Fossey, Jesse L. Palmer, Felita W. Zhang, Veronica M. Lucian, Luca Cera, John F. Zimmerman, F. John Burpo, Kevin Kit Parker. Matter DOI: https://doi.org/10.1016/j.matt.2020.06.001 Published:June 29, 2020

This paper is behind a paywall.

While this is the first time I’ve featured clothing/armour that’s protective against explosions I have on at least two occasions featured bulletproof clothing in a Canadian context. A November 4, 2013 posting had a story about a Toronto-based tailoring establishment, Garrison Bespoke, that was going to publicly test a bulletproof business suit. Should you be interested, it is possible to order the suit here. There’s also a February 11, 2020 posting announcing research into “Comfortable, bulletproof clothing for Canada’s Department of National Defence.”

Bionanomotors for bio-inspired robots on the battlefield

An October 9, 2019 news item on ScienceDaily provides some insight into the latest US Army research into robots,

In an effort to make robots more effective and versatile teammates for Soldiers in combat, Army researchers are on a mission to understand the value of the molecular living functionality of muscle, and the fundamental mechanics that would need to be replicated in order to artificially achieve the capabilities arising from the proteins responsible for muscle contraction.

Caption: Army researchers are on a mission to understand the value of the molecular ‘living’ functionality of muscle, and the fundamental mechanics that would need to be replicated in order to artificially achieve the capabilities arising from the proteins responsible for muscle contraction. Credit: US Army-Shutterstock

An October 8, 2019 US Army Research Laboratory news release (also on EurekAlert but published on October 9, 2019), which originated the news item, delves further into the research,

Bionanomotors, like myosins that move along actin networks, are responsible for most methods of motion in all life forms. Thus, the development of artificial nanomotors could be game-changing in the field of robotics research.

Researchers from the U.S. Army Combat Capabilities Development Command’s [CCDC] Army Research Laboratory [ARL] have been looking to identify a design that would allow the artificial nanomotor to take advantage of Brownian motion, the property of particles to agitatedly move simply because they are warm.

The CCDC ARL researchers believe understanding and developing these fundamental mechanics are a necessary foundational step toward making informed decisions on the viability of new directions in robotics involving the blending of synthetic biology, robotics, and dynamics and controls engineering.

“By controlling the stiffness of different geometrical features of a simple lever-arm design, we found that we could use Brownian motion to make the nanomotor more capable of reaching desirable positions for creating linear motion,” said Dean Culver, a researcher in CCDC ARL’s Vehicle Technology Directorate. “This nano-scale feature translates to more energetically efficient actuation at a macro scale, meaning robots that can do more for the warfighter over a longer amount of time.”

According to Culver, the descriptions of protein interactions in muscle contraction are typically fairly high-level. More specifically, rather than describing the forces that act on an individual protein to seek its counterpart, prescribed or empirical rate functions that dictate the conditions under which a binding or a release event occurs have been used by the research community to replicate this biomechanical process.

“These widely accepted muscle contraction models are akin to a black-box understanding of a car engine,” Culver said. “More gas, more power. It weighs this much and takes up this much space. Combustion is involved. But, you can’t design a car engine with that kind of surface-level information. You need to understand how the pistons work, and how finely injection needs to be tuned. That’s a component-level understanding of the engine. We dive into the component-level mechanics of the built-up protein system and show the design and control value of living functionality as well as a clearer understanding of design parameters that would be key to synthetically reproducing such living functionality.”

Culver stated that the capacity for Brownian motion to kick a tethered particle from a disadvantageous elastic position to an advantageous one, in terms of energy production for a molecular motor, has been illustrated by ARL at a component level, a crucial step in the design of artificial nanomotors that offer the same performance capabilities as biological ones.

“This research adds a key piece of the puzzle for fast, versatile robots that can perform autonomous tactical maneuver and reconnaissance functions,” Culver said. “These models will be integral to the design of distributed actuators that are silent, low thermal signature and efficient – features that will make these robots more impactful in the field.”

Culver noted that they are silent because the muscles don’t make a lot of noise when they actuate, especially compared to motors or servos, cold because the amount of heat generation in a muscle is far less than a comparable motor, and efficient because of the advantages of the distributed chemical energy model and potential escape via Brownian motion.

According to Culver, the breadth of applications for actuators inspired by the biomolecular machines in animal muscles is still unknown, but many of the existing application spaces have clear Army applications such as bio-inspired robotics, nanomachines and energy harvesting.

“Fundamental and exploratory research in this area is therefore a wise investment for our future warfighter capabilities,” Culver said.

Moving forward, there are two primary extensions of this research.

“First, we need to better understand how molecules, like the tethered particle discussed in our paper, interact with each other in more complicated environments,” Culver said. “In the paper, we see how a tethered particle can usefully harness Brownian motion to benefit the contraction of the muscle overall, but the particle in this first model is in an idealized environment. In our bodies, it’s submerged in a fluid carrying many different ions and energy-bearing molecules in solution. That’s the last piece of the puzzle for the single-motor, nano-scale models of molecular motors.”

The second extension, stated Culver, is to repeat this study with a full 3-D model, paving the way to scaling up to practical designs.

Also notable is the fact that because this research is so young, ARL researchers used this project to establish relationships with other investigators in the academic community.

“Leaning on their expertise will be critical in the years to come, and we’ve done a great job of reaching out to faculty members and researchers from places like the University of Washington, Duke University and Carnegie Mellon University,” Culver said.

According to Culver, taking this research project into the next steps with help from collaborative partners will lead to tremendous capabilities for future Soldiers in combat, a critical requirement considering the nature of the ever-changing battlefield.

Here’s a link to and a citation for the paper,

A Dynamic Escape Problem of Molecular Motors by Dean Culver, Bryan Glaz, Samuel Stanton. J Biomech Eng. Paper No: BIO-18-1527 https://doi.org/10.1115/1.4044580 Published Online: August 1, 2019

This paper is behind a paywall.

Comfortable, bulletproof clothing for Canada’s Department of National Defence

h/t to Miriam Halpenny’s October 14, 2019 Castanet article as seen on the Vancouverisawesome website for this news about bulletproof clothing being developed for Canada’s National Department of Defence. I found a September 4, 2019 University of British Columbia Okanagan news release describing the research and the funds awarded to it,

The age-old technique of dressing in layers is a tried and tested way to protect from the elements. Now thanks to $1.5 million in new funding for UBC’s Okanagan campus, researchers are pushing the practice to new limits by creating a high-tech body armour solution with multiple layers of protection against diverse threats.

“Layers are great for regulating body heat, protecting us from inclement weather and helping us to survive in extreme conditions,” says Keith Culver, director of UBC’s Survive and Thrive Applied Research (STAR) initiative, which is supporting the network of researchers who will be working together over the next three years. “The idea is to design and integrate some of the most advanced fabrics and materials into garments that are comfortable, practical and can even stop a bullet.”

The research network working to develop these new Comfort-Optimized Materials For Operational Resilience, Thermal-transport and Survivability (COMFORTS) aims to create a futuristic new body armour solution by combining an intelligent, moisture-wicking base layer that has insulating properties with a layer of lightweight, ballistic-resistant material using cross-linker technology. It will also integrate a water, dust and gas repellent outer layer and will be equipped with comfort sensors to monitor the wearer’s response to extreme conditions.

“Although the basic idea seems simple, binding all these different materials and technologies together into a smart armour solution that is durable, reliable and comfortable is incredibly complex,” says Kevin Golovin, assistant professor of mechanical engineering at UBCO and principal investigator of the COMFORTS research network. “We’re putting into practice years of research and expertise in materials science to turn the concept into reality.”

The COMFORTS network is a collaboration between the University of British Columbia, the University of Alberta and the University of Victoria and is supported by a number of industrial partners. The network has received a $1.5M contribution agreement from the Department of National Defence through its Innovation for Defence Excellence and Security (IDEaS) program, designed to support innovation in defence and security.

“The safety and security threats faced by our military are ever-changing,” says Culver. “Hazards extend beyond security threats from foreign forces to natural disasters now occurring more frequently than ever before. Almost every year we’re seeing natural disasters, forest fires and floods that put not just ordinary Canadians at risk but also the personnel that respond directly to those threats. Our goal is to better protect those who put their lives on the line to protect the rest of us.”

While the initial COMFORTS technologies developed will be for defence and security applications, Culver says the potential extends well beyond the military.

“Imagine a garment that could keep its users comfortable and safe as they explore the tundra of the Canadian arctic, fight a raging forest fire or respond to a corrosive chemical spill,” says Culver. “I imagine everyone from first responders to soldiers to extreme athletes being impacted by this kind of innovation in protective clothing.”

The research will be ongoing with eight projects planned over the next three years. Some of the protective materials testing will take place at UBC’s STAR Impact Research Facility (SIRF), located just north of UBC’s Okanagan campus. The ballistic and blast simulation facility is the only one of its kind in Canada—it supports research and testing of ballistic and blast-resistant armour, ceramic and other composite materials, as well as helmets and other protective gear.

“I anticipate we will see some exciting new, field-tested technologies developed within the next few years,” says Culver. “I look forward to seeing where this collaboration will lead us.”

To learn more about the COMFORTS project, visit: ok.ubc.ca/okanagan-stories/textile-tech

UBC Expert Q&A

Western Canada primed to be defense and security research hotspot

World-class vineyards and sunny lakeside resorts have long been the reputation for BC’s Okanagan Valley. That reputation has expanded with Kelowna’s growth as a tech hub, according to Professor Keith Culver, director of UBC’s Survive and Thrive Research (STAR) initiative, but core expertise in defense and security research has also been rapidly expanding since UBC launched the STAR initiative five years ago.

Culver is a professor, legal theorist, self-described convener and coach with proven expertise assembling multi-disciplinary research teams working at the vanguard of innovation. One of these teams, led by Assistant Professor of Mechanical Engineering Kevin Golovin, was recently awarded a $1.5 million contract by the Department of National Defense to develop next-generation, high-performance body armour that increases the safety and comfort of Canadian soldiers.

What is UBC’s STAR initiative?

UBC STAR is a group of researchers and partners working together to solve human performance challenges. We know that solving complex problems requires a multi-disciplinary approach, so we build teams with specialized expertise from across both our campuses and other Western Canadian universities. Then we blend that expertise with the know-how and production capabilities of private and public sector partners to put solutions into practice. Above all, STAR helps university researchers and partners to work together in new, more productive ways.

You recently received considerable new funding from the Department of National Defence. Can you tell us about that research

A team of researchers from UBC, the University of Alberta and the University of Victoria have established a research network to invent and test new materials for the protection of humans operating in extreme environments – in this case, soldiers doing their jobs on foot. Assistant Professor Kevin Golovin of UBC Okanagan’s School of Engineering is leading the network with support from UBC STAR. The network brings together three leading Western Canadian universities to work together with industry to develop new technologies for the defence and security sector.

The network is developing several kinds of protective materials and hazard sensors for use in protective armour for soldiers and first responders. The name of the network captures its focus nicely: Comfort-Optimized Materials For Operational Resilience, Thermal-transport and Survivabilty (COMFORTS). Researchers in engineering, chemistry and other disciplines are developing new textile technologies and smart armour solutions that will be rigorously tested for thermal resistance to increase soldier comfort. We’re fortunate to be working with a great group of companies ready to turn our research into solutions ready for use. We’ll help to solve the challenges facing Canadian first responders and soldiers while enabling Canadian companies to sell those solutions to international markets.

What does the safety and security landscape look like in Western Canada?

I think there’s a perception out there that this kind of research is only happening in places like Halifax, Toronto or Waterloo. Western Canadian expertise is sometimes overlooked by Ottawa and Toronto, but there’s incredible expertise and cutting-edge research happening here in the west, and we are fortunate to have a strong private sector partner community that understands safety and security problems in military contexts, and in forestry, mining and wildfire and flood response. Our understanding of hazardous environments gives us a head start in putting technologies and strategies to work safely in extreme conditions, and we’re coming to realize that our creative solutions can both help Canadians and others around the world.

Why do companies want to work with UBC STAR and its Western Canadian partners?

We have great researchers and great facilities – our blast simulator and ballistics range are second to none – but we offer much more than expertise and equipment. UBC STAR is fundamentally about making the most of collaboration. We work together with our partners to understand the nature of problems and what could contribute to a solution. We readily draw on expertise from multiple universities and firms to assemble the right team. And we know that we are in the middle of a great living lab for testing solutions –with rural and urban areas of varying sizes, climates and terrains. We’re situated in an ideal place to work through technology development, while identifying the strategies and standards needed to put innovative technology to good use.

How do you expect this sector to develop over the next decade?

I see a boom coming in this sector. In Canada, and around the world, we are witnessing a rise in natural disasters that put first responders and others at risk, and our research can help improve their safety. At the same time, we are seeing a rise in global political tensions calling for Canadian military deployment in peacekeeping and other support roles. Our military needs help protecting its members so they can do their jobs in dangerous places. And, of course, when we develop protective materials for first responders and soldiers, the same solutions can be easily adapted for use in sport and health – such as protecting children playing contact sports or our aging population from slip and fall injuries. I think I speak for everyone involved in this research when I say that it’s incredibly rewarding to see how solutions found addressing one question often have far broader benefits for Canadians in every walk of life.

To learn more about STAR, visit: star.ubc.ca

About UBC’s Okanagan campus

UBC’s Okanagan campus is an innovative hub for research and learning in the heart of British Columbia’s stunning Okanagan Valley. Ranked among the top 20 public universities in the world, UBC is home to bold thinking and discoveries that make a difference. Established in 2005, the Okanagan campus combines a globally recognized UBC education with a tight-knit and entrepreneurial community that welcomes students and faculty from around the world.

To find out more, visit: ok.ubc.ca

Courtesy: UBC Okanagan

I have mentioned* bulletproof clothing here in a November 4, 2013 posting featuring a business suit that included carbon nanotubes providing protection from bullets. Here’s where you can order one.

*’mentioned’ was substituted for ‘featured’ as a grammar correction on July 6, 2020.

A Canadian military science posting in honour of Remembrance Day 2019

A surprising number of every day products, including items such as microwave ovens, penicillin, nylon, and more have come to us courtesy of military science. While we remember our fallen soldiers today (Remembrance Day 2019) in Canada and elsewhere throughout the Commonwealth countries, I thought it might be interesting to consider contemporary Canadian military science.

I’ve often wondered whether or not we have an equivalent to the US Army’s DARPA (Defense Advanced Research Projects Agency) and their other military research laboratories. We do! Defence Research and Development Canada (DRDC) or Recherche et développement pour la défense Canada (RDDC). Here’s more from its Wikipedia entry (Note: Links have been removed),

[…] is an agency of the Department of National Defence (DND), whose purpose is to provide the Canadian Armed Forces (CAF), other government departments, and public safety and national security communities with knowledge and technology.

DRDC has approximately 1,400 employees across eight research centres within Canada.

Civilian achievements

Over the years, researchers at DRDC, sometimes in partnership with the NRC [National Research Council of Canada] and others, have been responsible for numerous innovations and inventions of practical application in the civilian world. These include the G-suit, motorized wheelchair, the Alouette 1 satellite, Black Brant rocket, improvements to the carbon dioxide laser, flight data recorder, the Ballard fuel cell membrane, and the Bombsniffer (using gas chromatomography and ion mobility spectrometry).

While there’s been some type of organized Canadian military research since the 1920s (it wasn’t always called DRDC/RDDC), it’s only since 2018 that we have a rough equivalent to DARPA and, in our case known as, the Government of Canada Department of National Defence’s Innovation for Defence Excellence and Security (IDEaS). One of the currently available ‘challenges’ involves finding ways to make it easier to handle waste and manage energy in temporary camps, from the Pop-up City: Integrated Energy, Water and Waste Management Systems for Deployed Camps contest, which was launched August 21, 2019 and has a deadline of December 13, 2019,

The Canadian Armed Forces (CAF) must be ready to deploy on short notice, in any climate and for prolonged periods. The CAF presently relies on Relocatable Temporary Camps (RTCs) for its deployments that sustain personnel through demanding operational and environmental conditions.

The Department of National Defence’s (DND) Innovation for Defence Excellence and Security (IDEaS) Program is calling innovators on to propose and develop solutions that provide integrated energy, water and waste management systems for the CAF’s RTCs deployed in national and international operations.

The “Pop up City” Contest is a multi-phased contest for innovators to propose and develop reliable, energy efficient, integrated and scalable energy, water and waste management systems for RTCs. Contests are a competitive means of finding innovative solutions and awarding prizes to the best solutions derived from the innovation community. Specifically, this Contest is seeking solutions designed to manage the energy, water and waste needs of a 150 to 1,500-person RTC, operating in a temperate climate zone.

To standardize the required performance capacity for system designs, contestants will be supplied with per capita data for energy and water consumption, and waste production, along with representative annual climate data, including wind and solar patterns. Contestants will be asked to provide scalable solutions that can supply the requirements of RTCs over a 12-month period in this climate zone. System designs which would also allow for the occasional deployment to extreme hot and/or frigid climatic zones are strongly encouraged.

There are four competitive rounds culminating in the chance to win $2.0 million. Here are some details from the Pop-up City Contest FAQs (frequently asked questions),

Can a Contestant submit a solution for more than one technical domain (i.e. energy, water or waste) in Round 1 of the Contest?
Yes, Contestants can submit more than one proposal to the Contest. However, each solution must be submitted with its own complete application package. Contestants may not submit more than one solution proposal per technical domain.
Can I submit a proposal describing a solution that already exists?
Yes, Contestants may submit proposals describing solutions that are already at a high solution readiness level, with the caveat that Contestants must hold the Intellectual Property (IP) rights or have the necessary authorization from the owner of the IP rights to submit an application for the purpose of this Contest for any existing technologies submitted.
How do I apply for this Contest?
You must apply online through a Canada Post epost Connect™ service account. Before submitting your application materials (including a completed Application Form and a Declaration Form, and with documentation to demonstrate your eligibility), you must have a Canada Post epost Connect™ service account. It will take some time to register for an account, so it is strongly recommended that you initiate the registration process at least 2 weeks before you plan to submit your application materials. Instructions for creating an account are provided in Section 2.12 of the Contest Program guide.
What type of monetary awards will be given to contestants who are screened into Round 1 and Round 2 of the Contest?
If a Contestant is successful in Round 1, they will receive an award of $10, 000. If a Contestant is successful in Round 2, they will receive an award of $50,000.
Is the Contest a call for proposal process that will be awarding contracts to fund work based on project milestones?
No, there is no procurement related activity or contracting process associated with this Contest. Proposals submitted by Contestants may be awarded a monetary prize based on the overall ranking of their technical proposal and eligibility to participate within a specific Round of the Contest. DND will not be entering into a contract for work undertaken by Contestants should they be selected to advance within each Round of the Contest. However should a Contestant be offered a Contribution Agreement to build a prototype in Round 3 they will be reimbursed for eligible costs as stipulated in the Contribution Agreement based on project milestones.
If a Contestant has been selected to receive awards in Round 1 or 2, how will the money be disbursed?
Contestants will receive their award in a single payment via a grant agreement.
If a contestant has been selected to build their prototype in Round 3, how will funding be disbursed?
Should a Contestant be offered a Contribution Agreement (CA) to build their prototype, the CA will have clearly defined parameters based on milestone deliverables that will be used to reimburse eligible expenditures. If milestone deliverables demonstrate that progress in building and testing the prototype are not being met as per the CA, funding for the next stage of the project will not be approved and the CA will be terminated. Contestants will be removed from the Contest in these cases.
How will milestone deliverables be determined?
The milestone deliverables will be specified by the Contestant should they be selected to enter into a CA with DND in Round 3 of the Contest.
Do Contestants need to be a legal entity in Canada to participate in the Contest?
Yes, Contestants need to constitute an eligible recipient as listed in the Contest Program Guide, and be located in Canada to receive a grant payment or enter into a CA with DND on behalf of the Crown.
I am an Academic Institution located in Quebec. Must I abide by the M-30 law? What do I need to do to ensure that I am able to receive funds from the Government of Canada if I am selected in any Round within this Contest?
The Contest Program Guide (Annex C) provides some instructions and a form that must be completed by entities located in Quebec, to whom M-30 applies, and signed by the appropriate authority. You will not be able to receive any prize money or funding from the Government of Canada through this Contest until the appropriate authorization has been received by the IDEaS Program Office.
Will the winner of the Grand Prize of the Contest ($2.0M) be awarded a contract?
A grant agreement, not a contract, will be awarded to the Grand Prize winner at the end of this Contest.
Are there any terms and conditions associated with the Grand Prize?
It is expected that the Contestant who wins the $2.0M Grand Prize in Round 4 will use it to further develop the winning solution along the path to commercialization. Additional requirements will be stipulated in a grant agreement which will be used to disburse funding.
Who will sit on DND’s Technical Review Committee (TRC)?
The TRC will consist of Department of National Defence (DND) scientific personnel as well as members of the Canadian Armed Forces. In addition, select subject matter experts from other Government Departments may be invited to support activities associated with the TRC.
Who will sit on DND Senior Management Funding Oversite Committee?
The Senior Management Funding Oversight Committee (SMFOC), is comprised of the Director General responsible for the IDEaS Program, and the Directors General responsible for DND and/or Canadian Armed Forces organization(s) associated with the Contest.
How will submissions be selected to move on from Rounds 1, 2, 3 and 4 and who will select the Grand prize winner?
The TRC, along with the SMFOC will assess Round 1, 2, 3 and 4 submissions including the Grand Prize winner.
What can the $1.5M in Contribution Agreement for Round 3 winners be used for?
The Contribution Agreement will support the development of a prototype system proposed in Round 2. A list of eligible costs will be provided to Contestants. Recipients may be required to leverage additional funding to build their prototype depending on the cost of their proposal.
What will the Department of National Defence use the information from the prototype for?
This information will help inform the state of the current capabilities of the innovation community in these domains.
Can Contestants submit solutions that have already been integrated in 2 or 3 technical domains in Round 1 of the Contest?
Yes, however each solution must be submitted individually for assessment to determine if it will be screened into Round 2 of the Contest.

Questions from Information Session
The following questions were posed in the English information session held September 11, 2019 for the Pop up City contest. If you did not receive a response to your question, please contact the program directly at: IDEaSContests.IDEeSConcours@forces.gc.ca.

Waste
What’s in scope for solid waste? Food waste? Human waste? Non-organic waste? Does ‘solid waste’ include non-organic solid waste? Can a solution address organic waste only, as opposed to organic and non-organic waste?
Answer: Human waste is included in the black water volumes provided. Wet waste can be assumed to be organic kitchen waste. Dry waste is a mixture of various materials “shipping, office, plastic, metal and textile” in origin. Assumptions on composition of dry solid waste can be made based on total energy content provided of 15 MJ/kg. Organic and inorganic waste can be managed separately, however all solid waste output from the RTC will be measured.
Are solid waste generation numbers segregated from gray water and black water effluents?
Answer: Yes. Per capita volumes of grey and black water are provided and do not overlap with per capita weights of dry and wet solid waste provided.
Do waste management systems need to handle both solid and liquid waste, or just one stream such as grey or black water?
Answer: Solutions must propose management for both solid and liquid waste.
Would grey water be acceptable for reuse in some capacity?
Answer: Yes, strategies for grey water recycling can be proposed.
….

It seems to me this kind of pop up city waster and energy management solution could be very useful in disaster relief.

In any event and not to lose sight of the purpose for this day, I leave you to your remembrances of those who fought and died or were injured in the various wars and military actions where we have participated. Lest we forget.

AI (artificial intelligence) and a hummingbird robot

Every once in a while I stumble across a hummingbird robot story (my August 12, 2011 posting and my August 1, 2014 posting). Here’s what the hummingbird robot looks like now (hint: there’s a significant reduction in size),

Caption: Purdue University researchers are building robotic hummingbirds that learn from computer simulations how to fly like a real hummingbird does. The robot is encased in a decorative shell. Credit: Purdue University photo/Jared Pike

I think this is the first time I’ve seen one of these projects not being funded by the military, which explains why the researchers are more interested in using these hummingbird robots for observing wildlife and for rescue efforts in emergency situations. Still, they do acknowledge theses robots could also be used in covert operations.

From a May 9, 2019 news item on ScienceDaily,

What can fly like a bird and hover like an insect?

Your friendly neighborhood hummingbirds. If drones had this combo, they would be able to maneuver better through collapsed buildings and other cluttered spaces to find trapped victims.

Purdue University researchers have engineered flying robots that behave like hummingbirds, trained by machine learning algorithms based on various techniques the bird uses naturally every day.

This means that after learning from a simulation, the robot “knows” how to move around on its own like a hummingbird would, such as discerning when to perform an escape maneuver.

Artificial intelligence, combined with flexible flapping wings, also allows the robot to teach itself new tricks. Even though the robot can’t see yet, for example, it senses by touching surfaces. Each touch alters an electrical current, which the researchers realized they could track.

“The robot can essentially create a map without seeing its surroundings. This could be helpful in a situation when the robot might be searching for victims in a dark place — and it means one less sensor to add when we do give the robot the ability to see,” said Xinyan Deng, an associate professor of mechanical engineering at Purdue.

The researchers even have a video,

A May 9, 2019 Purdue University news release (also on EurekAlert), which originated the news item, provides more detail,


The researchers [presented] their work on May 20 at the 2019 IEEE International Conference on Robotics and Automation in Montreal. A YouTube video is available at https://www.youtube.com/watch?v=hl892dHqfA&feature=youtu.be. [it’s the video I’ve embedded in the above]

Drones can’t be made infinitely smaller, due to the way conventional aerodynamics work. They wouldn’t be able to generate enough lift to support their weight.

But hummingbirds don’t use conventional aerodynamics – and their wings are resilient. “The physics is simply different; the aerodynamics is inherently unsteady, with high angles of attack and high lift. This makes it possible for smaller, flying animals to exist, and also possible for us to scale down flapping wing robots,” Deng said.

Researchers have been trying for years to decode hummingbird flight so that robots can fly where larger aircraft can’t. In 2011, the company AeroVironment, commissioned by DARPA, an agency within the U.S. Department of Defense, built a robotic hummingbird that was heavier than a real one but not as fast, with helicopter-like flight controls and limited maneuverability. It required a human to be behind a remote control at all times.

Deng’s group and her collaborators studied hummingbirds themselves for multiple summers in Montana. They documented key hummingbird maneuvers, such as making a rapid 180-degree turn, and translated them to computer algorithms that the robot could learn from when hooked up to a simulation.

Further study on the physics of insects and hummingbirds allowed Purdue researchers to build robots smaller than hummingbirds – and even as small as insects – without compromising the way they fly. The smaller the size, the greater the wing flapping frequency, and the more efficiently they fly, Deng says.

The robots have 3D-printed bodies, wings made of carbon fiber and laser-cut membranes. The researchers have built one hummingbird robot weighing 12 grams – the weight of the average adult Magnificent Hummingbird – and another insect-sized robot weighing 1 gram. The hummingbird robot can lift more than its own weight, up to 27 grams.

Designing their robots with higher lift gives the researchers more wiggle room to eventually add a battery and sensing technology, such as a camera or GPS. Currently, the robot needs to be tethered to an energy source while it flies – but that won’t be for much longer, the researchers say.

The robots could fly silently just as a real hummingbird does, making them more ideal for covert operations. And they stay steady through turbulence, which the researchers demonstrated by testing the dynamically scaled wings in an oil tank.

The robot requires only two motors and can control each wing independently of the other, which is how flying animals perform highly agile maneuvers in nature.

“An actual hummingbird has multiple groups of muscles to do power and steering strokes, but a robot should be as light as possible, so that you have maximum performance on minimal weight,” Deng said.

Robotic hummingbirds wouldn’t only help with search-and-rescue missions, but also allow biologists to more reliably study hummingbirds in their natural environment through the senses of a realistic robot.

“We learned from biology to build the robot, and now biological discoveries can happen with extra help from robots,” Deng said.
Simulations of the technology are available open-source at https://github.com/
purdue-biorobotics/flappy
.

Early stages of the work, including the Montana hummingbird experiments in collaboration with Bret Tobalske’s group at the University of Montana, were financially supported by the National Science Foundation.

The researchers have three paper on arxiv.org for open access peer review,

Learning Extreme Hummingbird Maneuvers on Flapping Wing Robots
Fan Fei, Zhan Tu, Jian Zhang, and Xinyan Deng
Purdue University, West Lafayette, IN, USA
https://arxiv.org/abs/1902.0962

Biological studies show that hummingbirds can perform extreme aerobatic maneuvers during fast escape. Given a sudden looming visual stimulus at hover, a hummingbird initiates a fast backward translation coupled with a 180-degree yaw turn, which is followed by instant posture stabilization in just under 10 wingbeats. Consider the wingbeat frequency of 40Hz, this aggressive maneuver is carried out in just 0.2 seconds. Inspired by the hummingbirds’ near-maximal performance during such extreme maneuvers, we developed a flight control strategy and experimentally demonstrated that such maneuverability can be achieved by an at-scale 12- gram hummingbird robot equipped with just two actuators. The proposed hybrid control policy combines model-based nonlinear control with model-free reinforcement learning. We use model-based nonlinear control for nominal flight control, as the dynamic model is relatively accurate for these conditions. However, during extreme maneuver, the modeling error becomes unmanageable. A model-free reinforcement learning policy trained in simulation was optimized to ‘destabilize’ the system and maximize the performance during maneuvering. The hybrid policy manifests a maneuver that is close to that observed in hummingbirds. Direct simulation-to-real transfer is achieved, demonstrating the hummingbird-like fast evasive maneuvers on the at-scale hummingbird robot.

Acting is Seeing: Navigating Tight Space Using Flapping Wings
Zhan Tu, Fan Fei, Jian Zhang, and Xinyan Deng
Purdue University, West Lafayette, IN, USA
https://arxiv.org/abs/1902.0868

Wings of flying animals can not only generate lift and control torques but also can sense their surroundings. Such dual functions of sensing and actuation coupled in one element are particularly useful for small sized bio-inspired robotic flyers, whose weight, size, and power are under stringent constraint. In this work, we present the first flapping-wing robot using its flapping wings for environmental perception and navigation in tight space, without the need for any visual feedback. As the test platform, we introduce the Purdue Hummingbird, a flapping-wing robot with 17cm wingspan and 12 grams weight, with a pair of 30-40Hz flapping wings driven by only two actuators. By interpreting the wing loading feedback and its variations, the vehicle can detect the presence of environmental changes such as grounds, walls, stairs, obstacles and wind gust. The instantaneous wing loading can be obtained through the measurements and interpretation of the current feedback by the motors that actuate the wings. The effectiveness of the proposed approach is experimentally demonstrated on several challenging flight tasks without vision: terrain following, wall following and going through a narrow corridor. To ensure flight stability, a robust controller was designed for handling unforeseen disturbances during the flight. Sensing and navigating one’s environment through actuator loading is a promising method for mobile robots, and it can serve as an alternative or complementary method to visual perception.

Flappy Hummingbird: An Open Source Dynamic Simulation of Flapping Wing Robots and Animals
Fan Fei, Zhan Tu, Yilun Yang, Jian Zhang, and Xinyan Deng
Purdue University, West Lafayette, IN, USA
https://arxiv.org/abs/1902.0962

Insects and hummingbirds exhibit extraordinary flight capabilities and can simultaneously master seemingly conflicting goals: stable hovering and aggressive maneuvering, unmatched by small scale man-made vehicles. Flapping Wing Micro Air Vehicles (FWMAVs) hold great promise for closing this performance gap. However, design and control of such systems remain challenging due to various constraints. Here, we present an open source high fidelity dynamic simulation for FWMAVs to serve as a testbed for the design, optimization and flight control of FWMAVs. For simulation validation, we recreated the hummingbird-scale robot developed in our lab in the simulation. System identification was performed to obtain the model parameters. The force generation, open- loop and closed-loop dynamic response between simulated and experimental flights were compared and validated. The unsteady aerodynamics and the highly nonlinear flight dynamics present challenging control problems for conventional and learning control algorithms such as Reinforcement Learning. The interface of the simulation is fully compatible with OpenAI Gym environment. As a benchmark study, we present a linear controller for hovering stabilization and a Deep Reinforcement Learning control policy for goal-directed maneuvering. Finally, we demonstrate direct simulation-to-real transfer of both control policies onto the physical robot, further demonstrating the fidelity of the simulation.

Enjoy!

Graphene and smart textiles

Here’s one of the more recent efforts to create fibres that are electronic and capable of being woven into a smart textile. (Details about a previous effort can be found at the end of this post.) Now for this one, from a Dec. 3, 2018 news item on ScienceDaily,

The quest to create affordable, durable and mass-produced ‘smart textiles’ has been given fresh impetus through the use of the wonder material Graphene.

An international team of scientists, led by Professor Monica Craciun from the University of Exeter Engineering department, has pioneered a new technique to create fully electronic fibres that can be incorporated into the production of everyday clothing.

A Dec. 3, 2018 University of Exeter press release (also on EurekAlert), provides more detail about the problems associated with wearable electronics and the solution being offered (Note: A link has been removed),

Currently, wearable electronics are achieved by essentially gluing devices to fabrics, which can mean they are too rigid and susceptible to malfunctioning.

The new research instead integrates the electronic devices into the fabric of the material, by coating electronic fibres with light-weight, durable components that will allow images to be shown directly on the fabric.

The research team believe that the discovery could revolutionise the creation of wearable electronic devices for use in a range of every day applications, as well as health monitoring, such as heart rates and blood pressure, and medical diagnostics.

The international collaborative research, which includes experts from the Centre for Graphene Science at the University of Exeter, the Universities of Aveiro and Lisbon in Portugal, and CenTexBel in Belgium, is published in the scientific journal Flexible Electronics.

Professor Craciun, co-author of the research said: “For truly wearable electronic devices to be achieved, it is vital that the components are able to be incorporated within the material, and not simply added to it.

Dr Elias Torres Alonso, Research Scientist at Graphenea and former PhD student in Professor Craciun’s team at Exeter added “This new research opens up the gateway for smart textiles to play a pivotal role in so many fields in the not-too-distant future.  By weaving the graphene fibres into the fabric, we have created a new technique to all the full integration of electronics into textiles. The only limits from now are really within our own imagination.”

At just one atom thick, graphene is the thinnest substance capable of conducting electricity. It is very flexible and is one of the strongest known materials. The race has been on for scientists and engineers to adapt graphene for the use in wearable electronic devices in recent years.

This new research used existing polypropylene fibres – typically used in a host of commercial applications in the textile industry – to attach the new, graphene-based electronic fibres to create touch-sensor and light-emitting devices.

The new technique means that the fabrics can incorporate truly wearable displays without the need for electrodes, wires of additional materials.

Professor Saverio Russo, co-author and from the University of Exeter Physics department, added: “The incorporation of electronic devices on fabrics is something that scientists have tried to produce for a number of years, and is a truly game-changing advancement for modern technology.”

Dr Ana Neves, co-author and also from Exeter’s Engineering department added “The key to this new technique is that the textile fibres are flexible, comfortable and light, while being durable enough to cope with the demands of modern life.”

In 2015, an international team of scientists, including Professor Craciun, Professor Russo and Dr Ana Neves from the University of Exeter, have pioneered a new technique to embed transparent, flexible graphene electrodes into fibres commonly associated with the textile industry.

Here’s a link to and a citation for the paper,

Graphene electronic fibres with touch-sensing and light-emitting functionalities for smart textiles by Elias Torres Alonso, Daniela P. Rodrigues, Mukond Khetani, Dong-Wook Shin, Adolfo De Sanctis, Hugo Joulie, Isabel de Schrijver, Anna Baldycheva, Helena Alves, Ana I. S. Neves, Saverio Russo & Monica F. Craciun. Flexible Electronicsvolume 2, Article number: 25 (2018) DOI: https://doi.org/10.1038/s41528-018-0040-2 Published 25 September 2018

This paper is open access.

I have an earlier post about an effort to weave electronics into textiles for soldiers, from an April 5, 2012 posting,

I gather that today’s soldier (aka, warfighter)  is carrying as many batteries as weapons. Apparently, the average soldier carries a couple of kilos worth of batteries and cables to keep their various pieces of equipment operational. The UK’s Centre for Defence Enterprise (part of the Ministry of Defence) has announced that this situation is about to change as a consequence of a recently funded research project with a company called Intelligent Textiles. From Bob Yirka’s April 3, 2012 news item for physorg.com,

To get rid of the cables, a company called Intelligent Textiles has come up with a type of yarn that can conduct electricity, which can be woven directly into the fabric of the uniform. And because they allow the uniform itself to become one large conductive unit, the need for multiple batteries can be eliminated as well.

I dug down to find more information about this UK initiative and the Intelligent Textiles company but the trail seems to end in 2015. Still, I did find a Canadian connection (for those who don’t know I’m a Canuck) and more about Intelligent Textile’s work with the British military in this Sept. 21, 2015 article by Barry Collins for alphr.com (Note: Links have been removed),

A two-person firm operating from a small workshop in Staines-upon-Thames, Intelligent Textiles has recently landed a multimillion-pound deal with the US Department of Defense, and is working with the Ministry of Defence (MoD) to bring its potentially life-saving technology to British soldiers. Not bad for a company that only a few years ago was selling novelty cushions.

Intelligent Textiles was born in 2002, almost by accident. Asha Peta Thompson, an arts student at Central Saint Martins, had been using textiles to teach children with special needs. That work led to a research grant from Brunel University, where she was part of a team tasked with creating a “talking jacket” for the disabled. The garment was designed to help cerebral palsy sufferers to communicate, by pressing a button on the jacket to say “my name is Peter”, for example, instead of having a Stephen Hawking-like communicator in front of them.

Another member of that Brunel team was engineering lecturer Dr Stan Swallow, who was providing the electronics expertise for the project. Pretty soon, the pair realised the prototype waistcoat they were working on wasn’t going to work: it was cumbersome, stuffed with wires, and difficult to manufacture. “That’s when we had the idea that we could weave tiny mechanical switches into the surface of the fabric,” said Thompson.

The conductive weave had several advantages over packing electronics into garments. “It reduces the amount of cables,” said Thompson. “It can be worn and it’s also washable, so it’s more durable. It doesn’t break; it can be worn next to the skin; it’s soft. It has all the qualities of a piece of fabric, so it’s a way of repackaging the electronics in a way that’s more user-friendly and more comfortable.” The key to Intelligent Textiles’ product isn’t so much the nature of the raw materials used, but the way they’re woven together. “All our patents are in how we weave the fabric,” Thompson explained. “We weave two conductive yarns to make a tiny mechanical switch that is perfectly separated or perfectly connected. We can weave an electronic circuit board into the fabric itself.”

Intelligent Textiles’ big break into the military market came when they met a British textiles firm that was supplying camouflage gear to the Canadian armed forces. [emphasis mine] The firm was attending an exhibition in Canada and invited the Intelligent Textiles duo to join them. “We showed a heated glove and an iPod controller,” said Thompson. “The Canadians said ‘that’s really fantastic, but all we need is power. Do you think you could weave a piece of fabric that distributes power?’ We said, ‘we’re already doing it’.”Before long it wasn’t only power that the Canadians wanted transmitted through the fabric, but data.

“The problem a soldier faces at the moment is that he’s carrying 60 AA batteries [to power all the equipment he carries],” said Thompson. “He doesn’t know what state of charge those batteries are at, and they’re incredibly heavy. He also has wires and cables running around the system. He has snag hazards – when he’s going into a firefight, he can get caught on door handles and branches, so cables are a real no-no.”

The Canadians invited the pair to speak at a NATO conference, where they were approached by military brass with more familiar accents. “It was there that we were spotted by the British MoD, who said ‘wow, this is a British technology but you’re being funded by Canada’,” said Thompson. That led to £235,000 of funding from the Centre for Defence Enterprise (CDE) – the money they needed to develop a fabric wiring system that runs all the way through the soldier’s vest, helmet and backpack.

There are more details about the 2015 state of affairs, textiles-wise, in a March 11, 2015 article by Richard Trenholm for CNET.com (Note: A link has been removed),

Speaking at the Wearable Technology Show here, Swallow describes IT [Intelligent Textiles]L as a textile company that “pretends to be a military company…it’s funny how you slip into these domains.”

One domain where this high-tech fabric has seen frontline action is in the Canadian military’s IAV Stryker armoured personnel carrier. ITL developed a full QWERTY keyboard in a single piece of fabric for use in the Stryker, replacing a traditional hardware keyboard that involved 100 components. Multiple components allow for repair, but ITL knits in redundancy so the fabric can “degrade gracefully”. The keyboard works the same as the traditional hardware, with the bonus that it’s less likely to fall on a soldier’s head, and with just one glaring downside: troops can no longer use it as a step for getting in and out of the vehicle.

An armoured car with knitted controls is one thing, but where the technology comes into its own is when used about the person. ITL has worked on vests like the JTAC, a system “for the guys who call down airstrikes” and need “extra computing oomph.” Then there’s SWIPES, a part of the US military’s Nett Warrior system — which uses a chest-mounted Samsung Galaxy Note 2 smartphone — and British military company BAE’s Broadsword system.

ITL is currently working on Spirit, a “truly wearable system” for the US Army and United States Marine Corps. It’s designed to be modular, scalable, intuitive and invisible.

While this isn’t an ITL product, this video about Broadsword technology from BAE does give you some idea of what wearable technology for soldiers is like,

baesystemsinc

Uploaded on Jul 8, 2014

Broadsword™ delivers groundbreaking technology to the 21st Century warfighter through interconnecting components that inductively transfer power and data via The Spine™, a revolutionary e-textile that can be inserted into any garment. This next-generation soldier system offers enhanced situational awareness when used with the BAE Systems’ Q-Warrior® see-through display.

If anyone should have the latest news about Intelligent Textile’s efforts, please do share in the comments section.

I do have one other posting about textiles and the military, which is dated May 9, 2012, but while it does reference US efforts it is not directly related to weaving electronics into solder’s (warfighter’s) gear.

You can find CenTexBel (Belgian Textile Rsearch Centre) here and Graphenea here. Both are mentioned in the University of Exeter press release.

Terahertz imagers at your fingertips

It seems to me that I stumbled across quite a few carbon nanotube (CNT) stories in 2018. This one comes courtesy of Japan (from a June 28, 2018 news item on Nanowerk),

Researchers at Tokyo Tech have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Here’s a peek at an imager,

Figure 1. The CNT-based flexible THz imager (a) Resting on a fingertip, the CNT THz imager can easily wrap around curved surfaces. (b) Just by inserting and rotating a flexible THz imager attached to the fingertip, damage to a pipe was clearly detected. Courtesy Tokyo Tech

A June 28, 2018 Tokyo Tech Institute press release (also on Eurekalert), which originated the news item, provides more detail,

Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.

Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.

The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Tech, is a world-renowned expert in this field. In 2016, for example, he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.

Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.

Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.

Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.

By making use of a technology known as ionic liquid gating1, the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility, as shown in Figure 1 [see above].

“Additionally,” the team says, “we developed gate-free Fermi-level2 tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p-n junction3 CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope (see Figure 2.)

Non-contact, non-destructive visualization

Figure 2. Non-contact, non-destructive visualization

The CNT THz imager enabled clear, non-destructive visualization of a metal paper clip inside an envelope.

The bendability of the new THz imager and the possibility of even further fine-tuning will expand the range of CNT-based devices that could be developed in the near future.

Moreover, low-cost fabrication methods such as inkjet coating could make large-area THz imaging devices more readily available.

1 Ionic liquid gating

A technique used to modulate a material’s charge carrier properties.

2 Fermi level

A measure of the electrochemical potential for electrons, which is important for determining the electrical and thermal properties of solids. The term is named after the Italian–American physicist Enrico Fermi.

3 p-n junction

Refers to the interface between positive (p-type) and negative (n-type) semiconducting materials. These junctions form the basis of semiconductor electronic devices.

Here’s a link to and a citation for the paper,

Fermi-Level-Controlled Semiconducting-Separated Carbon Nanotube Films for Flexible Terahertz Imagers by Daichi Suzuki, Yuki Ochiai, Yota Nakagawa, Yuki Kuwahara, Takeshi Saito, and Yukio Kawano. ACS Appl. Nano Mater., 2018, 1 (6), pp 2469–2475 DOI: 10.1021/acsanm.8b00421 Publication Date (Web): June 6, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Injectable bandages for internal bleeding and hydrogel for the brain

This injectable bandage could be a gamechanger (as they say) if it can be taken beyond the ‘in vitro’ (i.e., petri dish) testing stage. A May 22, 2018 news item on Nanowerk makes the announcement (Note: A link has been removed),

While several products are available to quickly seal surface wounds, rapidly stopping fatal internal bleeding has proven more difficult. Now researchers from the Department of Biomedical Engineering at Texas A&M University are developing an injectable hydrogel bandage that could save lives in emergencies such as penetrating shrapnel wounds on the battlefield (Acta Biomaterialia, “Nanoengineered injectable hydrogels for wound healing application”).

A May 22, 2018 US National Institute of Biomedical Engineering and Bioengiineering news release, which originated the news item, provides more detail (Note: Links have been removed),

The researchers combined a hydrogel base (a water-swollen polymer) and nanoparticles that interact with the body’s natural blood-clotting mechanism. “The hydrogel expands to rapidly fill puncture wounds and stop blood loss,” explained Akhilesh Gaharwar, Ph.D., assistant professor and senior investigator on the work. “The surface of the nanoparticles attracts blood platelets that become activated and start the natural clotting cascade of the body.”

Enhanced clotting when the nanoparticles were added to the hydrogel was confirmed by standard laboratory blood clotting tests. Clotting time was reduced from eight minutes to six minutes when the hydrogel was introduced into the mixture. When nanoparticles were added, clotting time was significantly reduced, to less than three minutes.

In addition to the rapid clotting mechanism of the hydrogel composite, the engineers took advantage of special properties of the nanoparticle component. They found they could use the electric charge of the nanoparticles to add growth factors that efficiently adhered to the particles. “Stopping fatal bleeding rapidly was the goal of our work,” said Gaharwar. “However, we found that we could attach growth factors to the nanoparticles. This was an added bonus because the growth factors act to begin the body’s natural wound healing process—the next step needed after bleeding has stopped.”

The researchers were able to attach vascular endothelial growth factor (VEGF) to the nanoparticles. They tested the hydrogel/nanoparticle/VEGF combination in a cell culture test that mimics the wound healing process. The test uses a petri dish with a layer of endothelial cells on the surface that create a solid skin-like sheet. The sheet is then scratched down the center creating a rip or hole in the sheet that resembles a wound.

When the hydrogel containing VEGF bound to the nanoparticles was added to the damaged endothelial cell wound, the cells were induced to grow back and fill-in the scratched region—essentially mimicking the healing of a wound.

“Our laboratory experiments have verified the effectiveness of the hydrogel for initiating both blood clotting and wound healing,” said Gaharwar. “We are anxious to begin tests in animals with the hope of testing and eventual use in humans where we believe our formulation has great potential to have a significant impact on saving lives in critical situations.”

The work was funded by grant EB023454 from the National Institute of Biomedical Imaging and Bioengineering (NIBIB), and the National Science Foundation. The results were reported in the February issue of the journal Acta Biomaterialia.

The paper was published back in April 2018 and there was an April 2, 2018 Texas A&M University news release on EurekAlert making the announcement (and providing a few unique details),

A penetrating injury from shrapnel is a serious obstacle in overcoming battlefield wounds that can ultimately lead to death.Given the high mortality rates due to hemorrhaging, there is an unmet need to quickly self-administer materials that prevent fatality due to excessive blood loss.

With a gelling agent commonly used in preparing pastries, researchers from the Inspired Nanomaterials and Tissue Engineering Laboratory have successfully fabricated an injectable bandage to stop bleeding and promote wound healing.

In a recent article “Nanoengineered Injectable Hydrogels for Wound Healing Application” published in Acta Biomaterialia, Dr. Akhilesh K. Gaharwar, assistant professor in the Department of Biomedical Engineering at Texas A&M University, uses kappa-carrageenan and nanosilicates to form injectable hydrogels to promote hemostasis (the process to stop bleeding) and facilitate wound healing via a controlled release of therapeutics.

“Injectable hydrogels are promising materials for achieving hemostasis in case of internal injuries and bleeding, as these biomaterials can be introduced into a wound site using minimally invasive approaches,” said Gaharwar. “An ideal injectable bandage should solidify after injection in the wound area and promote a natural clotting cascade. In addition, the injectable bandage should initiate wound healing response after achieving hemostasis.”

The study uses a commonly used thickening agent known as kappa-carrageenan, obtained from seaweed, to design injectable hydrogels. Hydrogels are a 3-D water swollen polymer network, similar to Jell-O, simulating the structure of human tissues.

When kappa-carrageenan is mixed with clay-based nanoparticles, injectable gelatin is obtained. The charged characteristics of clay-based nanoparticles provide hemostatic ability to the hydrogels. Specifically, plasma protein and platelets form blood adsorption on the gel surface and trigger a blood clotting cascade.

“Interestingly, we also found that these injectable bandages can show a prolonged release of therapeutics that can be used to heal the wound” said Giriraj Lokhande, a graduate student in Gaharwar’s lab and first author of the paper. “The negative surface charge of nanoparticles enabled electrostatic interactions with therapeutics thus resulting in the slow release of therapeutics.”

Nanoparticles that promote blood clotting and wound healing (red discs), attached to the wound-filling hydrogel component (black) form a nanocomposite hydrogel. The gel is designed to be self-administered to stop bleeding and begin wound-healing in emergency situations. Credit: Lokhande, et al. 1

Here’s a link to and a citation for the paper,

Nanoengineered injectable hydrogels for wound healing application by Giriraj Lokhande, James K. Carrow, Teena Thakur, Janet R. Xavier, Madasamy Parani, Kayla J. Bayless, Akhilesh K. Gaharwar. Acta Biomaterialia Volume 70, 1 April 2018, Pages 35-47
https://doi.org/10.1016/j.actbio.2018.01.045

This paper is behind a paywall.

Hydrogel and the brain

It’s been an interesting week for hydrogels. On May 21, 2018 there was a news item on ScienceDaily about a bioengineered hydrogel which stimulated brain tissue growth after a stroke (mouse model),

In a first-of-its-kind finding, a new stroke-healing gel helped regrow neurons and blood vessels in mice with stroke-damaged brains, UCLA researchers report in the May 21 issue of Nature Materials.

“We tested this in laboratory mice to determine if it would repair the brain in a model of stroke, and lead to recovery,” said Dr. S. Thomas Carmichael, Professor and Chair of neurology at UCLA. “This study indicated that new brain tissue can be regenerated in what was previously just an inactive brain scar after stroke.”

The brain has a limited capacity for recovery after stroke and other diseases. Unlike some other organs in the body, such as the liver or skin, the brain does not regenerate new connections, blood vessels or new tissue structures. Tissue that dies in the brain from stroke is absorbed, leaving a cavity, devoid of blood vessels, neurons or axons, the thin nerve fibers that project from neurons.

After 16 weeks, stroke cavities in mice contained regenerated brain tissue, including new neural networks — a result that had not been seen before. The mice with new neurons showed improved motor behavior, though the exact mechanism wasn’t clear.

Remarkable stuff.

Embedded AI (artificial intelligence) with a variant of a memristor?

I don’t entirely get how ReRAM (resistive random access memory) is a variant of a memristor but I’m assuming Samuel K. Moore knows what he’s writing about since his May 16, 2018 posting is on the Nanoclast blog (hosted by the IEEE [Institute of Electrical and Electronics Engineers]), Note: Links have been removed,

Resistive RAM technology developer Crossbar says it has inked a deal with aerospace chip maker Microsemi allowing the latter to embed Crossbar’s nonvolatile memory on future chips. The move follows selection of Crossbar’s technology by a leading foundry for advanced manufacturing nodes. Crossbar is counting on resistive RAM (ReRAM) to enable artificial intelligence systems whose neural networks are housed within the device rather than in the cloud.

ReRAM is a variant of the memristor, a nonvolatile memory device whose resistance can be set or reset by a pulse of voltage. The variant Crossbar qualified for advanced manufacturing is called a filament device. It’s built within the layers above a chip’s silicon, where the IC’s interconnects go, and it’s made up of three layers: from top to bottom—silver, amorphous silicon, and tungsten. Voltage across the amorphous silicon causes a filament of silver atoms to cross the gap to the tungsten, making the memory cell conductive. Reversing the voltage pushes the silver back into place, cutting off conduction.

“The filament itself is only three to four nanometers wide,” says Sylvain Dubois, vice president of marketing and business development at Crossbar. “So the cell itself will be able to scale below 10-nanometers.” What’s more, the ratio between the current that flows when the device is on to when it is off is 1,000 or higher. …

A May 14, 2018 Crossbar news release describes some of the technical AI challenges,

“The biggest challenge facing engineers for AI today is overcoming the memory speed and power bottleneck in the current architecture to get faster data access while lowering the energy cost,” said Dubois. “By enabling a new, memory-centric non-volatile architecture like ReRAM, the entire trained model or knowledge base can be on-chip, connected directly to the neural network with the potential to achieve massive energy savings and performance improvements, resulting in a greatly improved battery life and a better user experience.”

Crossbar’s May 16, 2018 news release provides more detail about their ‘strategic collaboration’ with Microsemi Products (Note: A link has been removed),

Crossbar Inc., the ReRAM technology leader, announced an agreement with Microsemi Corporation, the largest U.S. commercial supplier of military and aerospace semiconductors, in which Microsemi will license Crossbar’s ReRAM core intellectual property. As part of the agreement, Microsemi and Crossbar will collaborate in the research, development and application of Crossbar’s proprietary ReRAM technology in next generation products from Microsemi that integrate Crossbar’s embedded ReRAM with Microsemi products manufactured at the 1x nm process node.

Military and aerospace, eh?