Tag Archives: Massachusetts Instittue of Technology

Colo(u)r-changing bandage for better compression

This is a structural colo(u)r story, from a May 29, 2018 news item on Nanowerk,

Compression therapy is a standard form of treatment for patients who suffer from venous ulcers and other conditions in which veins struggle to return blood from the lower extremities. Compression stockings and bandages, wrapped tightly around the affected limb, can help to stimulate blood flow. But there is currently no clear way to gauge whether a bandage is applying an optimal pressure for a given condition.

Now engineers at MIT {Massachusetts Institute of Technology] have developed pressure-sensing photonic fibers that they have woven into a typical compression bandage. As the bandage is stretched, the fibers change color. Using a color chart, a caregiver can stretch a bandage until it matches the color for a desired pressure, before, say, wrapping it around a patient’s leg.

The photonic fibers can then serve as a continuous pressure sensor — if their color changes, caregivers or patients can use the color chart to determine whether and to what degree the bandage needs loosening or tightening.

A May 29, 2018 MIT news release (also on EurekAlert), which originated the news item, provides more detail,

“Getting the pressure right is critical in treating many medical conditions including venous ulcers, which affect several hundred thousand patients in the U.S. each year,” says Mathias Kolle, assistant professor of mechanical engineering at MIT. “These fibers can provide information about the pressure that the bandage exerts. We can design them so that for a specific desired pressure, the fibers reflect an easily distinguished color.”

Kolle and his colleagues have published their results in the journal Advanced Healthcare Materials. Co-authors from MIT include first author Joseph Sandt, Marie Moudio, and Christian Argenti, along with J. Kenji Clark of the Univeristy of Tokyo, James Hardin of the United States Air Force Research Laboratory, Matthew Carty of Brigham and Women’s Hospital-Harvard Medical School, and Jennifer Lewis of Harvard University.

Natural inspiration

The color of the photonic fibers arises not from any intrinsic pigmentation, but from their carefully designed structural configuration. Each fiber is about 10 times the diameter of a human hair. The researchers fabricated the fiber from ultrathin layers of transparent rubber materials, which they rolled up to create a jelly-roll-type structure. Each layer within the roll is only a few hundred nanometers thick.

In this rolled-up configuration, light reflects off each interface between individual layers. With enough layers of consistent thickness, these reflections interact to strengthen some colors in the visible spectrum, for instance red, while diminishing the brightness of other colors. This makes the fiber appear a certain color, depending on the thickness of the layers within the fiber.

“Structural color is really neat, because you can get brighter, stronger colors than with inks or dyes just by using particular arrangements of transparent materials,” Sandt says. “These colors persist as long as the structure is maintained.”

The fibers’ design relies upon an optical phenomenon known as “interference,” in which light, reflected from a periodic stack of thin, transparent layers, can produce vibrant colors that depend on the stack’s geometric parameters and material composition. Optical interference is what produces colorful swirls in oily puddles and soap bubbles. It’s also what gives peacocks and butterflies their dazzling, shifting shades, as their feathers and wings are made from similarly periodic structures.

“My interest has always been in taking interesting structural elements that lie at the origin of nature’s most dazzling light manipulation strategies, to try recreating and employing them in useful applications,” Kolle says.

A multilayered approach

The team’s approach combines known optical design concepts with soft materials, to create dynamic photonic materials.

While a postdoc at Harvard in the group of Professor Joanna Aizenberg, Kolle was inspired by the work of Pete Vukusic, professor of biophotonics at the University of Exeter in the U.K., on Margaritaria nobilis, a tropical plant that produces extremely shiny blue berries. The fruits’ skin is made up of cells with a periodic cellulose structure, through which light can reflect to give the fruit its signature metallic blue color.

Together, Kolle and Vukusic sought ways to translate the fruit’s photonic architecture into a useful synthetic material. Ultimately, they fashioned multilayered fibers from stretchable materials, and assumed that stretching the fibers would change the individual layers’ thicknesses, enabling them to tune the fibers’ color. The results of these first efforts were published in Advanced Materials in 2013.

When Kolle joined the MIT faculty in the same year, he and his group, including Sandt, improved on the photonic fiber’s design and fabrication. In their current form, the fibers are made from layers of commonly used and widely available transparent rubbers, wrapped around highly stretchable fiber cores. Sandt fabricated each layer using spin-coating, a technique in which a rubber, dissolved into solution, is poured onto a spinning wheel. Excess material is flung off the wheel, leaving a thin, uniform coating, the thickness of which can be determined by the wheel’s speed.

For fiber fabrication, Sandt formed these two layers on top of a water-soluble film on a silicon wafer. He then submerged the wafer, with all three layers, in water to dissolve the water-soluble layer, leaving the two rubbery layers floating on the water’s surface. Finally, he carefully rolled the two transparent layers around a black rubber fiber, to produce the final colorful photonic fiber.

Reflecting pressure

The team can tune the thickness of the fibers’ layers to produce any desired color tuning, using standard optical modeling approaches customized for their fiber design.

“If you want a fiber to go from yellow to green, or blue, we can say, ‘This is how we have to lay out the fiber to give us this kind of [color] trajectory,'” Kolle says. “This is powerful because you might want to have something that reflects red to show a dangerously high strain, or green for ‘ok.’ We have that capacity.”

The team fabricated color-changing fibers with a tailored, strain-dependent color variation using the theoretical model, and then stitched them along the length of a conventional compression bandage, which they previously characterized to determine the pressure that the bandage generates when it’s stretched by a certain amount.

The team used the relationship between bandage stretch and pressure, and the correlation between fiber color and strain, to draw up a color chart, matching a fiber’s color (produced by a certain amount of stretching) to the pressure that is generated by the bandage.

To test the bandage’s effectiveness, Sandt and Moudio enlisted over a dozen student volunteers, who worked in pairs to apply three different compression bandages to each other’s legs: a plain bandage, a bandage threaded with photonic fibers, and a commercially-available bandage printed with rectangular patterns. This bandage is designed so that when it is applying an optimal pressure, users should see that the rectangles become squares.

Overall, the bandage woven with photonic fibers gave the clearest pressure feedback. Students were able to interpret the color of the fibers, and based on the color chart, apply a corresponding optimal pressure more accurately than either of the other bandages.

The researchers are now looking for ways to scale up the fiber fabrication process. Currently, they are able to make fibers that are several inches long. Ideally, they would like to produce meters or even kilometers of such fibers at a time.

“Currently, the fibers are costly, mostly because of the labor that goes into making them,” Kolle says. “The materials themselves are not worth much. If we could reel out kilometers of these fibers with relatively little work, then they would be dirt cheap.”

Then, such fibers could be threaded into bandages, along with textiles such as athletic apparel and shoes as color indicators for, say, muscle strain during workouts. Kolle envisions that they may also be used as remotely readable strain gauges for infrastructure and machinery.

“Of course, they could also be a scientific tool that could be used in a broader context, which we want to explore,” Kolle says.

Here’s what the bandage looks like,

Caption: Engineers at MIT have developed pressure-sensing photonic fibers that they have woven into a typical compression bandage. Credit Courtesy of the researchers

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

Stretchable Optomechanical Fiber Sensors for Pressure Determination in Compressive Medical Textiles by Joseph D. Sandt, Marie Moudio, J. Kenji Clark, James Hardin, Christian Argenti, Matthew Carty, Jennifer A. Lewis, Mathias Kolle. Advanced Healthcare Materials https://doi.org/10.1002/adhm.201800293 First published: 29 May 2018

This paper is behind a paywall.

Semi-living gloves as sensors

Researchers at the Massachusetts Institute of Technology (MIT) are calling it a new ‘living material’ according to a Feb. 16, 2017 news item on Nanowerk,

Engineers and biologists at MIT have teamed up to design a new “living material” — a tough, stretchy, biocompatible sheet of hydrogel injected with live cells that are genetically programmed to light up in the presence of certain chemicals.

Researchers have found that the hydrogel’s mostly watery environment helps keep nutrients and programmed bacteria alive and active. When the bacteria reacts to a certain chemical, the bacteria are programmed to light up, as seen on the left. Courtesy of the researchers

A Feb. 15, 2017 MIT news release, which originated the news item, provides more information about this work,

In a paper published this week in the Proceedings of the National Academy of Sciences, the researchers demonstrate the new material’s potential for sensing chemicals, both in the environment and in the human body.

The team fabricated various wearable sensors from the cell-infused hydrogel, including a rubber glove with fingertips that glow after touching a chemically contaminated surface, and bandages that light up when pressed against chemicals on a person’s skin.

Xuanhe Zhao, the Robert N. Noyce Career Development associate professor of mechanical engineering at MIT, says the group’s living material design may be adapted to sense other chemicals and contaminants, for uses ranging from crime scene investigation and forensic science, to pollution monitoring and medical diagnostics.

“With this design, people can put different types of bacteria in these devices to indicate toxins in the environment, or disease on the skin,” says Timothy Lu, associate professor of biological engineering and of electrical engineering and computer science. “We’re demonstrating the potential for living materials and devices.”

The paper’s co-authors are graduate students Xinyue Liu, Tzu-Chieh Tang, Eleonore Tham, Hyunwoo Yuk, and Shaoting Lin.

Infusing life in materials

Lu and his colleagues in MIT’s Synthetic Biology Group specialize in creating biological circuits, genetically reprogramming the biological parts in living cells such as E. coli to work together in sequence, much like logic steps in an electrical circuit. In this way, scientists can reengineer living cells to carry out specific functions, including the ability to sense and signal the presence of viruses and toxins.

However, many of these newly programmed cells have only been demonstrated in situ, within Petri dishes, where scientists can carefully control the nutrient levels necessary to keep the cells alive and active — an environment that has proven extremely difficult to replicate in synthetic materials.

“The challenge to making living materials is how to maintain those living cells, to make them viable and functional in the device,” Lu says. “They require humidity, nutrients, and some require oxygen. The second challenge is how to prevent them from escaping from the material.”

To get around these roadblocks, others have used freeze-dried chemical extracts from genetically engineered cells, incorporating them into paper to create low-cost, virus-detecting diagnostic strips. But extracts, Lu says, are not the same as living cells, which can maintain their functionality over a longer period of time and may have higher sensitivity for detecting pathogens.

Other groups have seeded heart muscle cells onto thin rubber films to make soft, “living” actuators, or robots. When bent repeatedly, however, these films can crack, allowing the live cells to leak out.

A lively host

Zhao’s group in MIT’s Soft Active Materials Laboratory has developed a material that may be ideal for hosting living cells. For the past few years, his team has come up with various formulations of hydrogel — a tough, highly stretchable, biocompatible material made from a mix of polymer and water. Their latest designs have contained up to 95 percent water, providing an environment which Zhao and Lu recognized might be suitable for sustaining living cells. The material also resists cracking even when repeatedly stretched and pulled — a property that could help contain cells within the material.

The two groups teamed up to integrate Lu’s genetically programmed bacterial cells into Zhao’s sheets of hydrogel material. They first fabricated layers of hydrogel and patterned narrow channels within the layers using 3-D printing and micromolding techniques. They fused the hydrogel to a layer of elastomer, or rubber, that is porous enough to let in oxygen. They then injected E. coli cells into the hydrogel’s channels. The cells were programmed to fluoresce, or light up, when in contact with certain chemicals that pass through the hydrogel, in this case a natural compound known as DAPG (2,4-diacetylphloroglucinol).

The researchers then soaked the hydrogel/elastomer material in a bath of nutrients which infused throughout the hydrogel and helped to keep the bacterial cells alive and active for several days.

To demonstrate the material’s potential uses, the researchers first fabricated a sheet of the material with four separate, narrow channels, each containing a type of bacteria engineered to glow green in response to a different chemical compound. They found each channel reliably lit up when exposed to its respective chemical.

Next, the team fashioned the material into a bandage, or “living patch,” patterned with channels containing bacteria sensitive to rhamnose, a naturally occurring sugar. The researchers swabbed a volunteer’s wrist with a cotton ball soaked in rhamnose, then applied the hydrogel patch, which instantly lit up in response to the chemical.

Finally, the researchers fabricated a hydrogel/elastomer glove whose fingertips contained swirl-like channels, each of which they filled with different chemical-sensing bacterial cells. Each fingertip glowed in response to picking up a cotton ball soaked with a respective compound.

The group has also developed a theoretical model to help guide others in designing similar living materials and devices.

“The model helps us to design living devices more efficiently,” Zhao says. “It tells you things like the thickness of the hydrogel layer you should use, the distance between channels, how to pattern the channels, and how much bacteria to use.”

Ultimately, Zhao envisions products made from living materials, such as gloves and rubber soles lined with chemical-sensing hydrogel, or bandages, patches, and even clothing that may detect signs of infection or disease.

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

Stretchable living materials and devices with hydrogel–elastomer hybrids hosting programmed cells by Xinyue Liu, Tzu-Chieh Tang, Eléonore Tham, Hyunwoo Yuk, Shaoting Lin, Timothy K. Lu, and Xuanhe Zhao. PNAS February 15, 2017 doi: 10.1073/pnas.1618307114 Published online before print February 15, 2017

This paper appears to be open access.

Commercializing nanotechnology: Peter Thiel’s Breakout Labs and Argonne National Laboratories

Breakout Labs

I last wrote about entrepreneur Peter Thiel’s Breakout Labs project in an Oct. 26, 2011 posting announcing its inception. An Oct. 6, 2015 Breakout Labs news release (received in my email) highlights a funding announcement for four startups of which at least three are nanotechnology-enabled,

Breakout Labs, a program of Peter Thiel’s philanthropic organization, the Thiel Foundation, announced today that four new companies advancing scientific discoveries in biomedical, chemical engineering, and nanotechnology have been selected for funding.

“We’re always hearing about bold new scientific research that promises to transform the world, but far too often the latest discoveries are left withering in a lab,” said Lindy Fishburne, Executive Director of Breakout Labs. “Our mission is to help a new type of scientist-entrepreneur navigate the startup ecosystem and build lasting companies that can make audacious scientific discoveries meaningful to everyday life. The four new companies joining the Breakout Labs portfolio – nanoGriptech, Maxterial, C2Sense, and CyteGen – embody that spirit and we’re excited to be working with them to help make their vision a reality.”

The future of adhesives: inspired by geckos

Inspired by the gecko’s ability to scuttle up walls and across ceilings due to their millions of micro/nano foot-hairs,nanoGriptech (http://nanogriptech.com/), based in Pittsburgh, Pa., is developing a new kind of microfiber adhesive material that is strong, lightweight, and reusable without requiring glues or producing harmful residues. Currently being tested by the U.S. military, NASA, and top global brands, nanoGriptech’s flagship product Setex™ is the first adhesive product of its kind that is not only strong and durable, but can also be manufactured at low cost, and at scale.

“We envision a future filled with no-leak biohazard enclosures, ergonomic and inexpensive car seats, extremely durable aerospace adhesives, comfortable prosthetic liners, high performance athletic wear, and widely available nanotechnology-enabled products manufactured less expensively — all thanks to the grippy little gecko,” said Roi Ben-Itzhak, CFO and VP of Business Development for nanoGriptech.

A sense of smell for the digital world

Despite the U.S. Department of Agriculture’s recent goals to drastically reduce food waste, most consumers don’t realize the global problem created by 1.3 billion metric tons of food wasted each year — clogging landfills and releasing unsustainable levels of methane gas into the atmosphere. Using technology developed at MIT’s Swager lab, Cambridge, Ma.-based C2Sense(http://www.c2sense.com/) is developing inexpensive, lightweight hand-held sensors based on carbon nanotubes which can detect fruit ripeness and meat, fish and poultry freshness. Smaller than a half of a business card, these sensors can be developed at very low cost, require very little power to operate, and can be easily integrated into most agricultural supply chains, including food storage packaging, to ensure that food is picked, stored, shipped, and sold at optimal freshness.

“Our mission is to bring a sense of smell to the digital world. With our technology, that package of steaks in your refrigerator will tell you when it’s about to go bad, recommend some recipe options and help build out your shopping list,” said Jan Schnorr, Chief Technology Officer of C2Sense.

Amazing metals that completely repel water

MaxterialTM, Inc. develops amazing materials that resist a variety of detrimental environmental effects through technology that emulates similar strategies found in nature, such as the self-cleaning lotus leaf and antifouling properties of crabs. By modifying the surface shape or texture of a metal, through a method that is very affordable and easy to introduce into the existing manufacturing process, Maxterial introduces a microlayer of air pockets that reduce contact surface area. The underlying material can be chemically the same as ever, retaining inherent properties like thermal and electrical conductivity. But through Maxterial’s technology, the metallic surface also becomes inherently water repellant. This property introduces the superhydrophobic maxterial as a potential solution to a myriad of problems, such as corrosion, biofouling, and ice formation. Maxterial is currently focused on developing durable hygienic and eco-friendly anti-corrosion coatings for metallic surfaces.

“Our process has the potential to create metallic objects that retain their amazing properties for the lifetime of the object – this isn’t an aftermarket coating that can wear or chip off,” said Mehdi Kargar, Co-founder and CEO of Maxterial, Inc. “We are working towards a day when shipping equipment can withstand harsh arctic environments, offshore structures can resist corrosion, and electronics can be fully submersible and continue working as good as new.”

New approaches to combat aging

CyteGen (http://cytegen.com/) wants to dramatically increase the human healthspan, tackle neurodegenerative diseases, and reverse age-related decline. What makes this possible now is new discovery tools backed by the dream team of interdisciplinary experts the company has assembled. CyteGen’s approach is unusually collaborative, tapping into the resources and expertise of world-renowned researchers across eight major universities to focus different strengths and perspectives to achieve the company’s goals. By approaching aging from a holistic, systematic point of view, rather than focusing solely on discrete definitions of disease, they have developed a new way to think about aging, and to develop treatments that can help people live longer, healthier lives.

“There is an assumption that aging necessarily brings the kind of physical and mental decline that results in Parkinson’s, Alzheimer’s, and other diseases. Evidence indicates otherwise, which is what spurred us to launch CyteGen,” said George Ugras, Co-Founder and President of CyteGen.

To date, Breakout Labs has invested in more than two dozen companies at the forefront of science, helping radical technologies get beyond common hurdles faced by early stage companies, and advance research and development to market much more quickly. Portfolio companies have raised more than six times the amount of capital invested in the program by the Thiel Foundation, and represent six Series A valuations ranging from $10 million to $60 million as well as one acquisition.

You can see the original Oct. 6, 2015 Breakout Labs news release here or in this Oct. 7, 2015 news item on Azonano.

Argonne National Labs and Nano Design Works (NDW) and the Argonne Collaborative Center for Energy Storage Science (ACCESS)

The US Department of Energy’s Argonne National Laboratory’s Oct. 6, 2015 press release by Greg Cunningham announced two initiatives meant to speed commercialization of nanotechnology-enabled products for the energy storage and other sectors,

Few technologies hold more potential to positively transform our society than energy storage and nanotechnology. Advances in energy storage research will revolutionize the way the world generates and stores energy, democratizing the delivery of electricity. Grid-level storage can help reduce carbon emissions through the increased adoption of renewable energy and use of electric vehicles while helping bring electricity to developing parts of the world. Nanotechnology has already transformed the electronics industry and is bringing a new set of powerful tools and materials to developers who are changing everything from the way energy is generated, stored and transported to how medicines are delivered and the way chemicals are produced through novel catalytic nanomaterials.

Recognizing the power of these technologies and seeking to accelerate their impact, the U.S. Department of Energy’s Argonne National Laboratory has created two new collaborative centers that provide an innovative pathway for business and industry to access Argonne’s unparalleled scientific resources to address the nation’s energy and national security needs. These centers will help speed discoveries to market to ensure U.S. industry maintains a lead in this global technology race.

“This is an exciting time for us, because we believe this new approach to interacting with business can be a real game changer in two areas of research that are of great importance to Argonne and the world,” said Argonne Director Peter B. Littlewood. “We recognize that delivering to market our breakthrough science in energy storage and nanotechnology can help ensure our work brings the maximum benefit to society.”

Nano Design Works (NDW) and the Argonne Collaborative Center for Energy Storage Science (ACCESS) will provide central points of contact for companies — ranging from large industrial entities to smaller businesses and startups, as well as government agencies — to benefit from Argonne’s world-class expertise, scientific tools and facilities.

NDW and ACCESS represent a new way to collaborate at Argonne, providing a single point of contact for businesses to assemble tailored interdisciplinary teams to address their most challenging R&D questions. The centers will also provide a pathway to Argonne’s fundamental research that is poised for development into practical products. The chance to build on existing scientific discovery is a unique opportunity for businesses in the nano and energy storage fields.

The center directors, Andreas Roelofs of NDW and Jeff Chamberlain of ACCESS, have both created startups in their careers and understand the value that collaboration with a national laboratory can bring to a company trying to innovate in technologically challenging fields of science. While the new centers will work with all sizes of companies, a strong emphasis will be placed on helping small businesses and startups, which are drivers of job creation and receive a large portion of the risk capital in this country.

“For a startup like mine to have the ability to tap the resources of a place like Argonne would have been immensely helpful,” said Roelofs. “We”ve seen the power of that sort of access, and we want to make it available to the companies that need it to drive truly transformative technologies to market.”

Chamberlain said his experience as an energy storage researcher and entrepreneur led him to look for innovative approaches to leveraging the best aspects of private industry and public science. The national laboratory system has a long history of breakthrough science that has worked its way to market, but shortening that journey from basic research to product has become a growing point of emphasis for the national laboratories over the past couple of decades. The idea behind ACCESS and NDW is to make that collaboration even easier and more powerful.

“Where ACCESS and NDW will differ from the conventional approach is through creating an efficient way for a business to build a customized, multi-disciplinary team that can address anything from small technical questions to broad challenges that require massive resources,” Chamberlain said. “That might mean assembling a team with chemists, physicists, computer scientists, materials engineers, imaging experts, or mechanical and electrical engineers; the list goes on and on. It’s that ability to tap the full spectrum of cross-cutting expertise at Argonne that will really make the difference.”

Chamberlain is deeply familiar with the potential of energy storage as a transformational technology, having led the formation of Argonne’s Joint Center for Energy Storage Research (JCESR). The center’s years-long quest to discover technologies beyond lithium-ion batteries has solidified the laboratory’s reputation as one of the key global players in battery research. ACCESS will tap Argonne’s full battery expertise, which extends well beyond JCESR and is dedicated to fulfilling the promise of energy storage.

Energy storage research has profound implications for energy security and national security. Chamberlain points out that approximately 1.3 billion people across the globe do not have access to electricity, with another billion having only sporadic access. Energy storage, coupled with renewable generation like solar, could solve that problem and eliminate the need to build out massive power grids. Batteries also have the potential to create a more secure, stable grid for countries with existing power systems and help fight global climate disruption through adoption of renewable energy and electric vehicles.

Argonne researchers are pursuing hundreds of projects in nanoscience, but some of the more notable include research into targeted drugs that affect only cancerous cells; magnetic nanofibers that can be used to create more powerful and efficient electric motors and generators; and highly efficient water filtration systems that can dramatically reduce the energy requirements for desalination or cleanup of oil spills. Other researchers are working with nanoparticles that create a super-lubricated state and other very-low friction coatings.

“When you think that 30 percent of a car engine’s power is sacrificed to frictional loss, you start to get an idea of the potential of these technologies,” Roelofs said. “But it’s not just about the ideas already at Argonne that can be brought to market, it’s also about the challenges for businesses that need Argonne-level resources. I”m convinced there are many startups out there working on transformational ideas that can greatly benefit from the help of a place Argonne to bring those ideas to fruition. That is what has me excited about ACCESS and NDW.”

For more information on ACCESS, see: access.anl.gov

For more information on NDW, see: nanoworks.anl.gov

You can read more about the announcement in an Oct. 6, 2015 article by Greg Watry for R&D magazine featuring an interview with Andreas Roelofs.