Category Archives: military

3D-printed ‘smart helmets’ for the military

Caption: The Rice University-designed smart helmet is intended to modernize standard-issue military helmets by 3D-printing a nanomaterial-enhanced exoskeleton with embedded sensors to actively protect the brain against kinetic or directed-energy effects. Credit: Rice University

Hopefully this will limit the number of head injuries suffered by soldiers.

Some years ago I was at dinner with friends when one of them, a doctor at the local hospital, told me that the Canadian military, which was in Afghanistan at the time, was dealing with a high number of head injury cases, in part due to the soldiers’ own protective gear.

For example, the protective helmet meant you were less likely to receive a catastrophic injury to your cranium (e.g., metal cracking through bone) but your head would be shaken and that isn’t good for anyone’s brain.

It would seem this project at Rice University (Texas, US) is designed to limit the problem of your own protective gear causing injury, from a November 10, 2021 Rice University news release (also on EurekAlert), Note: Links have been removed,

Rice University researchers have received $1.3 million from the Office of Naval Research through the Defense Research University Instrumentation Program to create the world’s first printable military “smart helmet” using industrial-grade 3D printers. 

Led by principal investigator Paul Cherukuri, executive director of Rice’s Institute of Biosciences and Bioengineering, the Smart Helmet program aims to modernize standard-issue military helmets by 3D-printing a nanomaterial-enhanced exoskeleton with embedded sensors to actively protect the brain against kinetic or directed-energy effects. 

Rice will utilize Carbon Inc.’s L1 printer to develop a strong-but-light military-grade helmet that incorporates advances in materials, image processing, artificial intelligence, haptic feedback and energy storage. The printer enables rapid prototyping that in turn simplifies the process of incorporating the sensors, cameras, batteries and wiring harnesses the program requires, Cherukuri said. 

“Current helmets have evolved little since the last century and are still heavy, bulky, passive devices,” he said. “Because of advances in sensors and additive manufacturing, we’re now reimagining the helmet as a 3D-printed, AI-enabled, ‘always-on’ wearable that detects threats near or far and is capable of launching countermeasures to protect soldiers, sailors, airmen and Marines. Essentially, we’re building J.A.R.V.I.S.”

The Smart Helmet program will use technology drawn from projects like the FlatCam, a system developed by co-investigator and electrical and computer engineer Ashok Veeraraghavan and his colleagues that incorporates sophisticated image processing to eliminate the need for bulky lenses, as well as Cherukuri’s Teslaphoresis, a kind of tractor beam for nanomaterials that could help create physical and electromagnetic shields inside the helmets. 

“A smart helmet task force has been assembled from some of the finest minds at Rice to tackle the challenge of creating a self-contained, intelligent system that protects the warfighter at all times,” Cherukuri said. The task force includes the labs of materials scientist Pulickel Ajayan, civil and environmental engineer and Rice Provost Reginald DesRoches, mechanical engineer Marcia O’Malley, chemist James Tour and Veeraraghavan.

While the location of the L1 has yet to be determined, a Carbon M2 printer will be located at the Oshman Engineering Design Kitchen (OEDK), where it will be available for projects other than the helmet. Rice undergraduates who design and build their mandated capstone projects at the OEDK are taking part in the helmet project, working alongside graduate students and postdoctoral researchers to develop the heads-up display.   

“We’ve got a lot of innovative tech in university labs that has never seen the light of day,” Cherukuri said. “We’re simply developing that technology into a device that gives the men and women protecting our country a real chance at coming home safe and sound. This is for them.”

The Storywrangler, tool exploring billions of social media messages, could predict political & financial turmoil

Being able to analyze Twitter messages (tweets) in real-time is amazing given what I wrote in this January 16, 2013 posting titled: “Researching tweets (the Twitter kind)” about the US Library of Congress and its attempts to access tweets for scholars,”

At least one of the reasons no one has received access to the tweets is that a single search of the archived (2006- 2010) tweets alone would take 24 hours, [emphases mine] …

So, bravo to the researchers at the University of Vermont (UVM). A July 16, 2021 news item on ScienceDaily makes the announcement,

For thousands of years, people looked into the night sky with their naked eyes — and told stories about the few visible stars. Then we invented telescopes. In 1840, the philosopher Thomas Carlyle claimed that “the history of the world is but the biography of great men.” Then we started posting on Twitter.

Now scientists have invented an instrument to peer deeply into the billions and billions of posts made on Twitter since 2008 — and have begun to uncover the vast galaxy of stories that they contain.

Caption: UVM scientists have invented a new tool: the Storywrangler. It visualizes the use of billions of words, hashtags and emoji posted on Twitter. In this example from the tool’s online viewer, three global events from 2020 are highlighted: the death of Iranian general Qasem Soleimani; the beginning of the COVID-19 pandemic; and the Black Lives Matter protests following the murder of George Floyd by Minneapolis police. The new research was published in the journal Science Advances. Credit: UVM

A July 15, 2021 UVM news release (also on EurekAlert but published on July 16, 2021) by Joshua Brown, which originated the news item, provides more detail abut the work,

“We call it the Storywrangler,” says Thayer Alshaabi, a doctoral student at the University of Vermont who co-led the new research. “It’s like a telescope to look — in real time — at all this data that people share on social media. We hope people will use it themselves, in the same way you might look up at the stars and ask your own questions.”

The new tool can give an unprecedented, minute-by-minute view of popularity, from rising political movements to box office flops; from the staggering success of K-pop to signals of emerging new diseases.

The story of the Storywrangler — a curation and analysis of over 150 billion tweets–and some of its key findings were published on July 16 [2021] in the journal Science Advances.

EXPRESSIONS OF THE MANY

The team of eight scientists who invented Storywrangler — from the University of Vermont, Charles River Analytics, and MassMutual Data Science [emphasis mine]– gather about ten percent of all the tweets made every day, around the globe. For each day, they break these tweets into single bits, as well as pairs and triplets, generating frequencies from more than a trillion words, hashtags, handles, symbols and emoji, like “Super Bowl,” “Black Lives Matter,” “gravitational waves,” “#metoo,” “coronavirus,” and “keto diet.”

“This is the first visualization tool that allows you to look at one-, two-, and three-word phrases, across 150 different languages [emphasis mine], from the inception of Twitter to the present,” says Jane Adams, a co-author on the new study who recently finished a three-year position as a data-visualization artist-in-residence at UVM’s Complex Systems Center.

The online tool, powered by UVM’s supercomputer at the Vermont Advanced Computing Core, provides a powerful lens for viewing and analyzing the rise and fall of words, ideas, and stories each day among people around the world. “It’s important because it shows major discourses as they’re happening,” Adams says. “It’s quantifying collective attention.” Though Twitter does not represent the whole of humanity, it is used by a very large and diverse group of people, which means that it “encodes popularity and spreading,” the scientists write, giving a novel view of discourse not just of famous people, like political figures and celebrities, but also the daily “expressions of the many,” the team notes.

In one striking test of the vast dataset on the Storywrangler, the team showed that it could be used to potentially predict political and financial turmoil. They examined the percent change in the use of the words “rebellion” and “crackdown” in various regions of the world. They found that the rise and fall of these terms was significantly associated with change in a well-established index of geopolitical risk for those same places.

WHAT’S HAPPENING?

The global story now being written on social media brings billions of voices — commenting and sharing, complaining and attacking — and, in all cases, recording — about world wars, weird cats, political movements, new music, what’s for dinner, deadly diseases, favorite soccer stars, religious hopes and dirty jokes.

“The Storywrangler gives us a data-driven way to index what regular people are talking about in everyday conversations, not just what reporters or authors have chosen; it’s not just the educated or the wealthy or cultural elites,” says applied mathematician Chris Danforth, a professor at the University of Vermont who co-led the creation of the StoryWrangler with his colleague Peter Dodds. Together, they run UVM’s Computational Story Lab.

“This is part of the evolution of science,” says Dodds, an expert on complex systems and professor in UVM’s Department of Computer Science. “This tool can enable new approaches in journalism, powerful ways to look at natural language processing, and the development of computational history.”

How much a few powerful people shape the course of events has been debated for centuries. But, certainly, if we knew what every peasant, soldier, shopkeeper, nurse, and teenager was saying during the French Revolution, we’d have a richly different set of stories about the rise and reign of Napoleon. “Here’s the deep question,” says Dodds, “what happened? Like, what actually happened?”

GLOBAL SENSOR

The UVM team, with support from the National Science Foundation [emphasis mine], is using Twitter to demonstrate how chatter on distributed social media can act as a kind of global sensor system — of what happened, how people reacted, and what might come next. But other social media streams, from Reddit to 4chan to Weibo, could, in theory, also be used to feed Storywrangler or similar devices: tracing the reaction to major news events and natural disasters; following the fame and fate of political leaders and sports stars; and opening a view of casual conversation that can provide insights into dynamics ranging from racism to employment, emerging health threats to new memes.

In the new Science Advances study, the team presents a sample from the Storywrangler’s online viewer, with three global events highlighted: the death of Iranian general Qasem Soleimani; the beginning of the COVID-19 pandemic; and the Black Lives Matter protests following the murder of George Floyd by Minneapolis police. The Storywrangler dataset records a sudden spike of tweets and retweets using the term “Soleimani” on January 3, 2020, when the United States assassinated the general; the strong rise of “coronavirus” and the virus emoji over the spring of 2020 as the disease spread; and a burst of use of the hashtag “#BlackLivesMatter” on and after May 25, 2020, the day George Floyd was murdered.

“There’s a hashtag that’s being invented while I’m talking right now,” says UVM’s Chris Danforth. “We didn’t know to look for that yesterday, but it will show up in the data and become part of the story.”

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

Storywrangler: A massive exploratorium for sociolinguistic, cultural, socioeconomic, and and political timelines using Twitter by Thayer Alshaabi, Jane L. Adams, Michael V. Arnold, Joshua R. Minot, David R. Dewhurst, Andrew J. Reagan, Christopher M. Danforth and Peter Sheridan Dodds. Science Advances 16 Jul 2021: Vol. 7, no. 29, eabe6534DOI: 10.1126/sciadv.abe6534 DOI: 10.1126/sciadv.abe6534

This paper is open access.

A couple of comments

I’m glad to see they are looking at phrases in many different languages. Although I do experience some hesitation when I consider the two companies involved in this research with the University of Vermont.

Charles River Analytics and MassMutual Data Science would not have been my first guess for corporate involvement but on re-examining the subhead and noting this: “potentially predict political and financial turmoil”, they make perfect sense. Charles River Analytics provides “Solutions to serve the warfighter …”, i.e., soldiers/the military, and MassMutual is an insurance company with a dedicated ‘data science space’ (from the MassMutual Explore Careers Data Science webpage),

What are some key projects that the Data Science team works on?

Data science works with stakeholders throughout the enterprise to automate or support decision making when outcomes are unknown. We help determine the prospective clients that MassMutual should market to, the risk associated with life insurance applicants, and which bonds MassMutual should invest in. [emphases mine]

Of course. The military and financial services. Delightfully, this research is at least partially (mostly?) funded on the public dime, the US National Science Foundation.

The coolest paint

It’s the ‘est’ of it all. The coolest, the whitest, the blackest … Scientists and artists are both pursuing the ‘est’. (More about the pursuit later in this posting.)

In this case, scientists have developed the coolest, whitest paint yet. From an April 16, 2021 news item on Nanowerk,

In an effort to curb global warming, Purdue University engineers have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say.

In October [2020], the team created an ultra-white paint that pushed limits on how white paint can be. Now they’ve outdone that. The newer paint not only is whiter but also can keep surfaces cooler than the formulation that the researchers had previously demonstrated.

“If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses,” said Xiulin Ruan, a Purdue professor of mechanical engineering.

Caption: Xiulin Ruan, a Purdue University professor of mechanical engineering, holds up his lab’s sample of the whitest paint on record. Credit: Purdue University/Jared Pike

This is nicely done. Researcher Xiulin Ruan is standing close to a structure that could be said to resemble the sun while in shirtsleeves and sunglasses and holding up a sample of his whitest paint in April (not usually a warm month in Indiana).

An April 15, 2021 Purdue University news release (also on EurkeAlert), which originated the news item, provides more detail about the work and hints about its commercial applications both civilian and military,

The researchers believe that this white may be the closest equivalent of the blackest black, “Vantablack,” [emphasis mine; see comments later in this post] which absorbs up to 99.9% of visible light. The new whitest paint formulation reflects up to 98.1% of sunlight – compared with the 95.5% of sunlight reflected by the researchers’ previous ultra-white paint – and sends infrared heat away from a surface at the same time.

Typical commercial white paint gets warmer rather than cooler. Paints on the market that are designed to reject heat reflect only 80%-90% of sunlight and can’t make surfaces cooler than their surroundings.

The team’s research paper showing how the paint works publishes Thursday (April 15 [2021]) as the cover of the journal ACS Applied Materials & Interfaces.

What makes the whitest paint so white

Two features give the paint its extreme whiteness. One is the paint’s very high concentration of a chemical compound called barium sulfate [emphasis mine] which is also used to make photo paper and cosmetics white.

“We looked at various commercial products, basically anything that’s white,” said Xiangyu Li, a postdoctoral researcher at the Massachusetts Institute of Technology who worked on this project as a Purdue Ph.D. student in Ruan’s lab. “We found that using barium sulfate, you can theoretically make things really, really reflective, which means that they’re really, really white.”

The second feature is that the barium sulfate particles are all different sizes in the paint. How much each particle scatters light depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.

“A high concentration of particles that are also different sizes gives the paint the broadest spectral scattering, which contributes to the highest reflectance,” said Joseph Peoples, a Purdue Ph.D. student in mechanical engineering.

There is a little bit of room to make the paint whiter, but not much without compromising the paint.”Although a higher particle concentration is better for making something white, you can’t increase the concentration too much. The higher the concentration, the easier it is for the paint to break or peel off,” Li said.

How the whitest paint is also the coolest

The paint’s whiteness also means that the paint is the coolest on record. Using high-accuracy temperature reading equipment called thermocouples, the researchers demonstrated outdoors that the paint can keep surfaces 19 degrees Fahrenheit cooler than their ambient surroundings at night. It can also cool surfaces 8 degrees Fahrenheit below their surroundings under strong sunlight during noon hours.

The paint’s solar reflectance is so effective, it even worked in the middle of winter. During an outdoor test with an ambient temperature of 43 degrees Fahrenheit, the paint still managed to lower the sample temperature by 18 degrees Fahrenheit.

This white paint is the result of six years of research building on attempts going back to the 1970s to develop radiative cooling paint as a feasible alternative to traditional air conditioners.

Ruan’s lab had considered over 100 different materials, narrowed them down to 10 and tested about 50 different formulations for each material. Their previous whitest paint was a formulation made of calcium carbonate, an earth-abundant compound commonly found in rocks and seashells.

The researchers showed in their study that like commercial paint, their barium sulfate-based paint can potentially handle outdoor conditions. The technique that the researchers used to create the paint also is compatible with the commercial paint fabrication process.

Patent applications for this paint formulation have been filed through the Purdue Research Foundation Office of Technology Commercialization. This research was supported by the Cooling Technologies Research Center at Purdue University and the Air Force Office of Scientific Research [emphasis mine] through the Defense University Research Instrumentation Program (Grant No.427 FA9550-17-1-0368). The research was performed at Purdue’s FLEX Lab and Ray W. Herrick Laboratories and the Birck Nanotechnology Center of Purdue’s Discovery Park.

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

Ultrawhite BaSO4 Paints and Films for Remarkable Daytime Subambient Radiative Cooling by Xiangyu Li, Joseph Peoples, Peiyan Yao, and Xiulin Ruan. ACS Appl. Mater. Interfaces 2021, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsami.1c02368 Publication Date:April 15, 2021 © 2021 American Chemical Society

This paper is behind a paywall.

Vantablack and the ongoing ‘est’ of blackest

Vantablack’s 99.9% light absorption no longer qualifies it for the ‘blackest black’. A newer standard for the ‘blackest black’ was set by the US National Institute of Standards and Technology at 99.99% light absorption with its N.I.S.T. ultra-black in 2019, although that too seems to have been bested.

I have three postings covering the Vantablack and blackest black story,

The third posting (December 2019) provides a brief summary of the story along with what was the latest from the US National Institute of Standards and Technology. There’s also a little bit about the ‘The Redemption of Vanity’ an art piece demonstrating the blackest black material from the Massachusetts Institute of Technology, which they state has 99.995% (at least) absorption of light.

From a science perspective, the blackest black would be useful for space exploration.

I am surprised there doesn’t seem to have been an artistic rush to work with the whitest white. That impression may be due to the fact that the feuds get more attention than quiet work.

Dark side to the whitest white?

Andrew Parnell, research fellow in physics and astronomy at the University of Sheffield (UK), mentions a downside to obtaining the material needed to produce this cooling white paint in a June 10, 2021 essay on The Conversation (h/t Fast Company), Note: Links have been removed,

… this whiter-than-white paint has a darker side. The energy required to dig up raw barite ore to produce and process the barium sulphite that makes up nearly 60% of the paint means it has a huge carbon footprint. And using the paint widely would mean a dramatic increase in the mining of barium.

Parnell ends his essay with this (Note: Links have been removed),

Barium sulphite-based paint is just one way to improve the reflectivity of buildings. I’ve spent the last few years researching the colour white in the natural world, from white surfaces to white animals. Animal hairs, feathers and butterfly wings provide different examples of how nature regulates temperature within a structure. Mimicking these natural techniques could help to keep our cities cooler with less cost to the environment.

The wings of one intensely white beetle species called Lepidiota stigma appear a strikingly bright white thanks to nanostructures in their scales, which are very good at scattering incoming light. This natural light-scattering property can be used to design even better paints: for example, by using recycled plastic to create white paint containing similar nanostructures with a far lower carbon footprint. When it comes to taking inspiration from nature, the sky’s the limit.

A lobster’s stretch and strength in a hydrogel

An MIT team has fabricated a hydrogel-based material that mimics the structure of the lobster’s underbelly, the toughest known hydrogel found in nature. Credits: Courtesy of the researchers

I love this lobster. In most photos, they’re food. This shows off the lobster as a living entity while showcasing its underbelly, which is what this story is all about. From an April 23, 2021 news item on phys.org (Note: A link has been removed),

A lobster’s underbelly is lined with a thin, translucent membrane that is both stretchy and surprisingly tough. This marine under-armor, as MIT [Massachusetts Institute of Technology] engineers reported in 2019, is made from the toughest known hydrogel in nature, which also happens to be highly flexible. This combination of strength and stretch helps shield a lobster as it scrabbles across the seafloor, while also allowing it to flex back and forth to swim.

Now a separate MIT team has fabricated a hydrogel-based material that mimics the structure of the lobster’s underbelly. The researchers ran the material through a battery of stretch and impact tests, and showed that, similar to the lobster underbelly, the synthetic material is remarkably “fatigue-resistant,” able to withstand repeated stretches and strains without tearing.

If the fabrication process could be significantly scaled up, materials made from nanofibrous hydrogels could be used to make stretchy and strong replacement tissues such as artificial tendons and ligaments.

The team’s results are published in the journal Matter. The paper’s MIT co-authors include postdocs Jiahua Ni and Shaoting Lin; graduate students Xinyue Liu and Yuchen Sun; professor of aeronautics and astronautics Raul Radovitzky; professor of chemistry Keith Nelson; mechanical engineering professor Xuanhe Zhao; and former research scientist David Veysset Ph.D. ’16, now at Stanford University; along with Zhao Qin, assistant professor at Syracuse University, and Alex Hsieh of the Army Research Laboratory.

An April 23, 2021 MIT news release (also on EurekAlert) by Jennifer Chu, which originated the news item, offers an overview of the groundwork for this latest research along with technical detail about the latest work,

Nature’s twist

In 2019, Lin and other members of Zhao’s group developed a new kind of fatigue-resistant material made from hydrogel — a gelatin-like class of materials made primarily of water and cross-linked polymers. They fabricated the material from ultrathin fibers of hydrogel, which aligned like many strands of gathered straw when the material was repeatedly stretched. This workout also happened to increase the hydrogel’s fatigue resistance.

“At that moment, we had a feeling nanofibers in hydrogels were important, and hoped to manipulate the fibril structures so that we could optimize fatigue resistance,” says Lin.

In their new study, the researchers combined a number of techniques to create stronger hydrogel nanofibers. The process starts with electrospinning, a fiber production technique that uses electric charges to draw ultrathin threads out of polymer solutions. The team used high-voltage charges to spin nanofibers from a polymer solution, to form a flat film of nanofibers, each measuring about 800 nanometers — a fraction of the diameter of a human hair.

They placed the film in a high-humidity chamber to weld the individual fibers into a sturdy, interconnected network, and then set the film in an incubator to crystallize the individual nanofibers at high temperatures, further strengthening the material.

They tested the film’s fatigue-resistance by placing it in a machine that stretched it repeatedly over tens of thousands of cycles. They also made notches in some films and observed how the cracks propagated as the films were stretched repeatedly. From these tests, they calculated that the nanofibrous films were 50 times more fatigue-resistant than the conventional nanofibrous hydrogels.

Around this time, they read with interest a study by Ming Guo, associate professor of mechanical engineering at MIT, who characterized the mechanical properties of a lobster’s underbelly. This protective membrane is made from thin sheets of chitin, a natural, fibrous material that is similar in makeup to the group’s hydrogel nanofibers.

Guo found that a cross-section of the lobster membrane revealed sheets of chitin stacked at 36-degree angles, similar to twisted plywood, or a spiral staircase. This rotating, layered configuration, known as a bouligand structure, enhanced the membrane’s properties of stretch and strength.

“We learned that this bouligand structure in the lobster underbelly has high mechanical performance, which motivated us to see if we could reproduce such structures in synthetic materials,” Lin says.

Angled architecture

Ni, Lin, and members of Zhao’s group teamed up with Nelson’s lab and Radovitzky’s group in MIT’s Institute for Soldier Nanotechnologies, and Qin’s lab at Syracuse University, to see if they could reproduce the lobster’s bouligand membrane structure using their synthetic, fatigue-resistant films.

“We prepared aligned nanofibers by electrospinning to mimic the chinic fibers existed in the lobster underbelly,” Ni says.

After electrospinning nanofibrous films, the researchers stacked each of five films in successive, 36-degree angles to form a single bouligand structure, which they then welded and crystallized to fortify the material. The final product measured 9 square centimeters and about 30 to 40 microns thick — about the size of a small piece of Scotch tape.

Stretch tests showed that the lobster-inspired material performed similarly to its natural counterpart, able to stretch repeatedly while resisting tears and cracks — a fatigue-resistance Lin attributes to the structure’s angled architecture.

“Intuitively, once a crack in the material propagates through one layer, it’s impeded by adjacent layers, where fibers are aligned at different angles,” Lin explains.

The team also subjected the material to microballistic impact tests with an experiment designed by Nelson’s group. They imaged the material as they shot it with microparticles at high velocity, and measured the particles’ speed before and after tearing through the material. The difference in velocity gave them a direct measurement of the material’s impact resistance, or the amount of energy it can absorb, which turned out to be a surprisingly tough 40 kilojoules per kilogram. This number is measured in the hydrated state.

“That means that a 5-millimeter steel ball launched at 200 meters per second would be arrested by 13 millimeters of the material,” Veysset says. “It is not as resistant as Kevlar, which would require 1 millimeter, but the material beats Kevlar in many other categories.”

It’s no surprise that the new material isn’t as tough as commercial antiballistic materials. It is, however, significantly sturdier than most other nanofibrous hydrogels such as gelatin and synthetic polymers like PVA. The material is also much stretchier than Kevlar. This combination of stretch and strength suggests that, if their fabrication can be sped up, and more films stacked in bouligand structures, nanofibrous hydrogels may serve as flexible and tough artificial tissues.

“For a hydrogel material to be a load-bearing artificial tissue, both strength and deformability are required,” Lin says. “Our material design could achieve these two properties.”

If you have the time and the interest, do check out the April 23, 2021 MIT news release, which features a couple of informative GIFs.

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

Strong fatigue-resistant nanofibrous hydrogels inspired by lobster underbelly by Jiahua Ni, Shaoting Lin, Zhao Qin, David Veysset, Xinyue Liu, Yuchen Sun, Alex J. Hsieh, Raul Radovitzky, Keith A. Nelson, Xuanhe Zhao. Matter, 2021; DOI: 10.1016/j.matt.2021.03.023 Published April 23, 2021

This paper is behind a paywall.

US Army researchers’ vision for artificial intelligence and ethics

The US Army peeks into a near future where humans and some forms of artificial intelligence (AI) work together in battle and elsewhere. From a February 3, 2021 U.S. Army Research Laboratory news release (also on EurekAlert but published on February 16, 2021),

The Army of the future will involve humans and autonomous machines working together to accomplish the mission. According to Army researchers, this vision will only succeed if artificial intelligence is perceived to be ethical.

Researchers, based at the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory, Northeastern University and the University of Southern California, expanded existing research to cover moral dilemmas and decision making that has not been pursued elsewhere.

This research, featured in Frontiers in Robotics and AI, tackles the fundamental challenge of developing ethical artificial intelligence, which, according to the researchers, is still mostly understudied.

“Autonomous machines, such as automated vehicles and robots, are poised to become pervasive in the Army,” said DEVCOM ARL researcher Dr. Celso de Melo, who is located at the laboratory’s ARL West regional site in Playa Vista, California. “These machines will inevitably face moral dilemmas where they must make decisions that could very well injure humans.”

For example, de Melo said, imagine that an automated vehicle is driving in a tunnel and suddenly five pedestrians cross the street; the vehicle must decide whether to continue moving forward injuring the pedestrians or swerve towards the wall risking the driver.

What should the automated vehicle do in this situation?

Prior work has framed these dilemmas in starkly simple terms, framing decisions as life and death, de Melo said, neglecting the influence of risk of injury to the involved parties on the outcome.

“By expanding the study of moral dilemmas to consider the risk profile of the situation, we significantly expanded the space of acceptable solutions for these dilemmas,” de Melo said. “In so doing, we contributed to the development of autonomous technology that abides to acceptable moral norms and thus is more likely to be adopted in practice and accepted by the general public.”

The researchers focused on this gap and presented experimental evidence that, in a moral dilemma with automated vehicles, the likelihood of making the utilitarian choice – which minimizes the overall injury risk to humans and, in this case, saves the pedestrians – was moderated by the perceived risk of injury to pedestrians and drivers.

In their study, participants were found more likely to make the utilitarian choice with decreasing risk to the driver and with increasing risk to the pedestrians. However, interestingly, most were willing to risk the driver (i.e., self-sacrifice), even if the risk to the pedestrians was lower than to the driver.

As a second contribution, the researchers also demonstrated that participants’ moral decisions were influenced by what other decision makers do – for instance, participants were less likely to make the utilitarian choice, if others often chose the non-utilitarian choice.

“This research advances the state-of-the-art in the study of moral dilemmas involving autonomous machines by shedding light on the role of risk on moral choices,” de Melo said. “Further, both of these mechanisms introduce opportunities to develop AI that will be perceived to make decisions that meet moral standards, as well as introduce an opportunity to use technology to shape human behavior and promote a more moral society.”

For the Army, this research is particularly relevant to Army modernization, de Melo said.

“As these vehicles become increasingly autonomous and operate in complex and dynamic environments, they are bound to face situations where injury to humans is unavoidable,” de Melo said. “This research informs how to navigate these moral dilemmas and make decisions that will be perceived as optimal given the circumstances; for example, minimizing overall risk to human life.”

Moving in to the future, researchers will study this type of risk-benefit analysis in Army moral dilemmas and articulate the corresponding practical implications for the development of AI systems.

“When deployed at scale, the decisions made by AI systems can be very consequential, in particular for situations involving risk to human life,” de Melo said. “It is critical that AI is able to make decisions that reflect society’s ethical standards to facilitate adoption by the Army and acceptance by the general public. This research contributes to realizing this vision by clarifying some of the key factors shaping these standards. This research is personally important because AI is expected to have considerable impact to the Army of the future; however, what kind of impact will be defined by the values reflected in that AI.”

The last time I had an item on a similar topic from the US Army Research Laboratory (ARL) it was in a March 26, 2018 posting; scroll down to the subhead, US Army (about 50% of the way down),

“As machine agents become more sophisticated and independent, it is critical for their human counterparts to understand their intent, behaviors, reasoning process behind those behaviors, and expected outcomes so the humans can properly calibrate their trust [emphasis mine] in the systems and make appropriate decisions,” explained ARL’s Dr. Jessie Chen, senior research psychologist.

This latest work also revolves around the issue of trust according to the last sentence in the 2021 study paper (link and citation to follow),

… Overall, these questions emphasize the importance of the kind of experimental work presented here, as it has the potential to shed light on people’s preferences about moral behavior in machines, inform the design of autonomous machines people are likely to trust and adopt, and, perhaps, even introduce an opportunity to promote a more moral society. [emphases mine]

From trust to adoption to a more moral society—that’s an interesting progression. For another more optimistic view of how robots and AI can have positive impacts there’s my March 29, 2021 posting, Little Lost Robot and humane visions of our technological future

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

Risk of Injury in Moral Dilemmas With Autonomous Vehicles by Celso M. de Melo, Stacy Marsella, and Jonathan Gratch. Front. Robot. AI [Frontiers in Robotics and AI], 20 January 2021 DOI: https://doi.org/10.3389/frobt.2020.572529

This paper is in an open access journal.

Use kombucha to produce bacterial cellulose

The combination of the US Army, bacterial cellulose, and kombucha seems a little unusual. However, this January 26, 2021 U.S. Army Research Laboratory news release (also on EurekAlert) provides some clues as to how this combination makes sense,

Kombucha tea, a trendy fermented beverage, inspired researchers to develop a new way to generate tough, functional materials using a mixture of bacteria and yeast similar to the kombucha mother used to ferment tea.

With Army funding, using this mixture, also called a SCOBY, or symbiotic culture of bacteria and yeast, engineers at MIT [Massachusetts Institute of Technology] and Imperial College London produced cellulose embedded with enzymes that can perform a variety of functions, such as sensing environmental pollutants and self-healing materials.

The team also showed that they could incorporate yeast directly into the cellulose, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage.

“This work provides insights into how synthetic biology approaches can harness the design of biotic-abiotic interfaces with biological organization over multiple length scales,” said Dr. Dawanne Poree, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory. “This is important to the Army as this can lead to new materials with potential applications in microbial fuel cells, sense and respond systems, and self-reporting and self-repairing materials.”

The research, published in Nature Materials was funded by ARO [Army Research Office] and the Army’s Institute for Soldier Nanotechnologies [ISN] at the Massachusetts Institute of Technology. The U.S. Army established the ISN in 2002 as an interdisciplinary research center devoted to dramatically improving the protection, survivability, and mission capabilities of the Soldier and Soldier-supporting platforms and systems.

“We foresee a future where diverse materials could be grown at home or in local production facilities, using biology rather than resource-intensive centralized manufacturing,” said Timothy Lu, an MIT associate professor of electrical engineering and computer science and of biological engineering.

Researchers produced cellulose embedded with enzymes, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage. These fermentation factories, which usually contain one species of bacteria and one or more yeast species, produce ethanol, cellulose, and acetic acid that gives kombucha tea its distinctive flavor.

Most of the wild yeast strains used for fermentation are difficult to genetically modify, so the researchers replaced them with a strain of laboratory yeast called Saccharomyces cerevisiae. They combined the yeast with a type of bacteria called Komagataeibacter rhaeticus that their collaborators at Imperial College London had previously isolated from a kombucha mother. This species can produce large quantities of cellulose.

Because the researchers used a laboratory strain of yeast, they could engineer the cells to do any of the things that lab yeast can do, such as producing enzymes that glow in the dark, or sensing pollutants or pathogens in the environment. The yeast can also be programmed so that they can break down pollutants/pathogens after detecting them, which is highly relevant to Army for chem/bio defense applications.

“Our community believes that living materials could provide the most effective sensing of chem/bio warfare agents, especially those of unknown genetics and chemistry,” said Dr. Jim Burgess ISN program manager for ARO.

The bacteria in the culture produced large-scale quantities of tough cellulose that served as a scaffold. The researchers designed their system so that they can control whether the yeast themselves, or just the enzymes that they produce, are incorporated into the cellulose structure. It takes only a few days to grow the material, and if left long enough, it can thicken to occupy a space as large as a bathtub.

“We think this is a good system that is very cheap and very easy to make in very large quantities,” said MIT graduate student and the paper’s lead author, Tzu-Chieh Tang. To demonstrate the potential of their microbe culture, which they call Syn-SCOBY, the researchers created a material incorporating yeast that senses estradiol, which is sometimes found as an environmental pollutant. In another version, they used a strain of yeast that produces a glowing protein called luciferase when exposed to blue light. These yeasts could be swapped out for other strains that detect other pollutants, metals, or pathogens.

The researchers are now looking into using the Syn-SCOBY system for biomedical or food applications. For example, engineering the yeast cells to produce antimicrobials or proteins that could benefit human health.

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

Living materials with programmable functionalities grown from engineered microbial co-cultures by Charlie Gilbert, Tzu-Chieh Tang, Wolfgang Ott, Brandon A. Dorr, William M. Shaw, George L. Sun, Timothy K. Lu & Tom Ellis. Nature Materials (2021) DOI: https://doi.org/10.1038/s41563-020-00857-5 Published: 11 January 2021

This paper is behind a paywall.

Spider web-like electronics with graphene

A spiderweb-inspired fractal design is used for hemispherical 3D photodetection to replicate the vision system of arthropods. (Sena Huh image)

This image is pretty and I’m pretty sure it’s an illustration and not a real photodetection system. Regardless, an Oct. 21, 2020 news item on Nanowerk describes the research into producing a real 3D hemispheric photodetector for biomedical imaging (Note: A link has been removed),

Purdue University innovators are taking cues from nature to develop 3D photodetectors for biomedical imaging.

The researchers used some architectural features from spider webs to develop the technology. Spider webs typically provide excellent mechanical adaptability and damage-tolerance against various mechanical loads such as storms.

“We employed the unique fractal design of a spider web for the development of deformable and reliable electronics that can seamlessly interface with any 3D curvilinear surface,” said Chi Hwan Lee, a Purdue assistant professor of biomedical engineering and mechanical engineering. “For example, we demonstrated a hemispherical, or dome-shaped, photodetector array that can detect both direction and intensity of incident light at the same time, like the vision system of arthropods such as insects and crustaceans.”

The Purdue technology uses the structural architecture of a spider web that exhibits a repeating pattern. This work is published in Advanced Materials (“Fractal Web Design of a Hemispherical Photodetector Array with Organic-Dye-Sensitized Graphene Hybrid Composites”).

An Oct. 21, 2020 Purdue University news release by Chris Adam, which originated the news item, delves further into the work,

Lee said this provides unique capabilities to distribute externally induced stress throughout the threads according to the effective ratio of spiral and radial dimensions and provides greater extensibility to better dissipate force under stretching. Lee said it also can tolerate minor cuts of the threads while maintaining overall strength and function of the entire web architecture.

“The resulting 3D optoelectronic architectures are particularly attractive for photodetection systems that require a large field of view and wide-angle antireflection, which will be useful for many biomedical and military imaging purposes,” said Muhammad Ashraful Alam, the Jai N. Gupta Professor of Electrical and Computer Engineering.

Alam said the work establishes a platform technology that can integrate a fractal web design with system-level hemispherical electronics and sensors, thereby offering several excellent mechanical adaptability and damage-tolerance against various mechanical loads.

“The assembly technique presented in this work enables deploying 2D deformable electronics in 3D architectures, which may foreshadow new opportunities to better advance the field of 3D electronic and optoelectronic devices,” Lee said.

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

Fractal Web Design of a Hemispherical Photodetector Array with Organic‐Dye‐Sensitized Graphene Hybrid Composites by Eun Kwang Lee, Ratul Kumar Baruah, Jung Woo Leem, Woohyun Park, Bong Hoon Kim, Augustine Urbas, Zahyun Ku, Young L. Kim, Muhammad Ashraful Alam, Chi Hwan Lee. Advanced Materials Volume 32, Issue 46 November 19, 2020 2004456 DOI: https://doi.org/10.1002/adma.202004456 First published online: 12 October 2020

This paper is behind a paywall.

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.