Author Archives: Maryse de la Giroday

Singing posters and talking shirts can communicate with you via car radio or smartphones

Singing posters and talking shirts haven’t gone beyond the prototype stage yet but I imagine University of Washington engineers are hoping this will happen sooner rather than later. In the meantime, they are  presenting their work at a conference according to a March 1, 2017 news item on ScienceDaily,

Imagine you’re waiting in your car and a poster for a concert from a local band catches your eye. What if you could just tune your car to a radio station and actually listen to that band’s music? Or perhaps you see the poster on the side of a bus stop. What if it could send your smartphone a link for discounted tickets or give you directions to the venue?

Going further, imagine you go for a run, and your shirt can sense your perspiration and send data on your vital signs directly to your phone.

A new technique pioneered by University of Washington engineers makes these “smart” posters and clothing a reality by allowing them to communicate directly with your car’s radio or your smartphone. For instance, bus stop billboards could send digital content about local attractions. A street sign could broadcast the name of an intersection or notice that it is safe to cross a street, improving accessibility for the disabled. In addition, clothing with integrated sensors could monitor vital signs and send them to a phone. [emphasis mine]

“What we want to do is enable smart cities and fabrics where everyday objects in outdoor environments — whether it’s posters or street signs or even the shirt you’re wearing — can ‘talk’ to you by sending information to your phone or car,” said lead faculty and UW assistant professor of computer science and engineering Shyam Gollakota.

“The challenge is that radio technologies like WiFi, Bluetooth and conventional FM radios would last less than half a day with a coin cell battery when transmitting,” said co-author and UW electrical engineering doctoral student Vikram Iyer. “So we developed a new way of communication where we send information by reflecting ambient FM radio signals that are already in the air, which consumes close to zero power.”

The UW team has — for the first time — demonstrated how to apply a technique called “backscattering” to outdoor FM radio signals. The new system transmits messages by reflecting and encoding audio and data in these signals that are ubiquitous in urban environments, without affecting the original radio transmissions. Results are published in a paper to be presented in Boston at the 14th USENIX Symposium on Networked Systems Design and Implementation in March [2017].

The team demonstrated that a “singing poster” for the band Simply Three placed at a bus stop could transmit a snippet of the band’s music, as well as an advertisement for the band, to a smartphone at a distance of 12 feet or to a car over 60 feet away. They overlaid the audio and data on top of ambient news signals from a local NPR radio station.

The University of Washington has produced a video demonstration of the technology

A March 1, 2017 University of Washington news release (also on EurekAlert), which originated the news item, explains further (Note: Links have been removed),

“FM radio signals are everywhere. You can listen to music or news in your car and it’s a common way for us to get our information,” said co-author and UW computer science and engineering doctoral student Anran Wang. “So what we do is basically make each of these everyday objects into a mini FM radio station at almost zero power.”

Such ubiquitous low-power connectivity can also enable smart fabric applications such as clothing integrated with sensors to monitor a runner’s gait and vital signs that transmits the information directly to a user’s phone. In a second demonstration, the researchers from the UW Networks & Mobile Systems Lab used conductive thread to sew an antenna into a cotton T-shirt, which was able to use ambient radio signals to transmit data to a smartphone at rates up to 3.2 kilobits per second.

The system works by taking an everyday FM radio signal broadcast from an urban radio tower. The “smart” poster or T-shirt uses a low-power reflector to manipulate the signal in a way that encodes the desired audio or data on top of the FM broadcast to send a “message” to the smartphone receiver on an unoccupied frequency in the FM radio band.

“Our system doesn’t disturb existing FM radio frequencies,” said co-author Joshua Smith, UW associate professor of computer science and engineering and of electrical engineering. “We send our messages on an adjacent band that no one is using — so we can piggyback on your favorite news or music channel without disturbing the original transmission.”

The team demonstrated three different methods for sending audio signals and data using FM backscatter: one simply overlays the new information on top of the existing signals, another takes advantage of unused portions of a stereo FM broadcast, and the third uses cooperation between two smartphones to decode the message.

“Because of the unique structure of FM radio signals, multiplying the original signal with the backscattered signal actually produces an additive frequency change,” said co-author Vamsi Talla, a UW postdoctoral researcher in computer science and engineering. “These frequency changes can be decoded as audio on the normal FM receivers built into cars and smartphones.”

In the team’s demonstrations, the total power consumption of the backscatter system was 11 microwatts, which could be easily supplied by a tiny coin-cell battery for a couple of years, or powered using tiny solar cells.

I cannot help but notice the interest in using this technology is for monitoring purposes, which could be benign or otherwise.

For anyone curious about the 14th USENIX Symposium on Networked Systems Design and Implementation being held March 27 – 29, 2017 in Boston, Massachusetts, you can find out more here.

Magic nano ink

Colour changes © Nature Communications 2017 / MPI [Max Planck Institute] for Intelligent Systems

A March 1, 2017 news item on Nanowerk helps to explain the image seen above (Note: A link has been removed),

Plasmonic printing produces resolutions several times greater than conventional printing methods. In plasmonic printing, colours are formed on the surfaces of tiny metallic particles when light excites their electrons to oscillate. Researchers at the Max Planck Institute for Intelligent Systems in Stuttgart have now shown how the colours of such metallic particles can be altered with hydrogen (Nature Communications, “Dynamic plasmonic colour display”).

The technique could open the way for animating ultra-high-resolution images and for developing extremely sharp displays. At the same time, it provides new approaches for encrypting information and detecting counterfeits.

A March 1, 2017 Max Planck Institute press release, which originated the news item, provides more  history and more detail about the research,

Glass artisans in medieval times exploited the effect long before it was even known. They coloured the magnificent windows of gothic cathedrals with nanoparticles of gold, which glowed red in the light. It was not until the middle of the 20th century that the underlying physical phenomenon was given a name: plasmons. These collective oscillations of free electrons are stimulated by the absorption of incident electromagnetic radiation. The smaller the metallic particles, the shorter the wavelength of the absorbed radiation. In some cases, the resonance frequency, i.e., the absorption maximum, falls within the visible light spectrum. The unabsorbed part of the spectrum is then scattered or reflected, creating an impression of colour. The metallic particles, which usually appear silvery, copper-coloured or golden, then take on entirely new colours.

A resolution of 100,000 dots per inch

Researchers are also taking advantage of the effect to develop plasmonic printing, in which tailor-made square metal particles are arranged in specific patterns on a substrate. The edge length of the particles is in the order of less than 100 nanometres (100 billionths of a metre). This allows a resolution of 100,000 dots per inch – several times greater than what today’s printers and displays can achieve.

For metallic particles measuring several 100 nanometres across, the resonance frequency of the plasmons lies within the visible light spectrum. When white light falls on such particles, they appear in a specific colour, for example red or blue. The colour of the metal in question is determined by the size of the particles and their distance from each other. These adjustment parameters therefore serve the same purpose in plasmonic printing as the palette of colours in painting.

The trick with the chemical reaction

The Smart Nanoplasmonics Research Group at the Max Planck Institute for Intelligent Systems in Stuttgart also makes use of this colour variability. They are currently working on making dynamic plasmonic printing. They have now presented an approach that allows them to alter the colours of the pixels predictably – even after an image has been printed. “The trick is to use magnesium. It can undergo a reversible chemical reaction in which the metallic character of the element is lost,” explains Laura Na Liu, who leads the Stuttgart research group. “Magnesium can absorb up to 7.6% of hydrogen by weight to form magnesium hydride, or MgH2”, Liu continues. The researchers coat the magnesium with palladium, which acts as a catalyst in the reaction.

During the continuous transition of metallic magnesium into non-metallic MgH2, the colour of some of the pixels changes several times. The colour change and the speed of the rate at which it proceeds follow a clear pattern. This is determined both by the size of and the distance between the individual magnesium particles as well as by the amount of hydrogen present.

In the case of total hydrogen saturation, the colour disappears completely, and the pixels reflect all the white light that falls on them. This is because the magnesium is no longer present in metallic form but only as MgH2. Hence, there are also no free metal electrons that can be made to oscillate.

Minerva’s vanishing act

The scientists demonstrated the effect of such dynamic colour behaviour on a plasmonic print of Minerva, the Roman goddess of wisdom, which also bore the logo of the Max Planck Society. They chose the size of their magnesium particles so that Minerva’s hair first appeared reddish, the head covering yellow, the feather crest red and the laurel wreath and outline of her face blue. They then washed the micro-print with hydrogen. A time-lapse film shows how the individual colours change. Yellow turns red, red turns blue, and blue turns white. After a few minutes all the colours disappear, revealing a white surface instead of Minerva.

The scientists also showed that this process is reversible by replacing the hydrogen stream with a stream of oxygen. The oxygen reacts with the hydrogen in the magnesium hydride to form water, so that the magnesium particles become metallic again. The pixels then change back in reverse order, and in the end Minerva appears in her original colours.

In a similar manner the researchers first made the micro image of a famous Van Gogh painting disappear and then reappear. They also produced complex animations that give the impression of fireworks.

The principle of a new encryption technique

Laura Na Liu can imagine using this principle in a new encryption technology. To demonstrate this, the group formed various letters with magnesium pixels. The addition of hydrogen then caused some letters to disappear over time, like the image of Minerva. “As for the rest of the letters, a thin oxide layer formed on the magnesium particles after exposing the sample in air for a short time before palladium deposition,” Liu explains. This layer is impermeable to hydrogen. The magnesium lying under the oxide layer therefore remains metallic − and visible − because light is able to excite the plasmons in the magnesium.

In this way it is possible to conceal a message, for example by mixing real and nonsensical information. Only the intended recipient is able to make the nonsensical information disappear and filter out the real message. For example, after decoding the message “Hartford” with hydrogen, only the words “art or” would remain visible. To make it more difficult to crack such encrypted messages, the group is currently working on a process that would require a precisely adjusted hydrogen concentration for deciphering.

Liu believes that the technology could also be used some day in the fight against counterfeiting. “For example, plasmonic security features could be printed on banknotes or pharmaceutical packs, which could later be checked or read only under specific conditions unknown to counterfeiters.”

It doesn’t necessarily have to be hydrogen

Laura Na Liu knows that the use of hydrogen makes some applications difficult and impractical for everyday use such as in mobile displays. “We see our work as a starting shot for a new principle: the use of chemical reactions for dynamic printing,” the Stuttgart physicist says. It is certainly conceivable that the research will soon lead to the discovery of chemical reactions for colour changes other than the phase transition between magnesium and magnesium dihydride, for example, reactions that require no gaseous reactants.

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

Dynamic plasmonic colour display by Xiaoyang Duan, Simon Kamin, & Na Liu. Nature Communications 8, Article number: 14606 (2017) doi:10.1038/ncomms14606 Published online: 24 February 2017

This paper is open access.

Making lead look like gold (so to speak)

Apparently you can make lead ‘look’ like gold if you can get it to reflect light in the same way. From a Feb. 28, 2017 news item on Nanowerk (Note: A link has been removed),

Since the Middle Ages, alchemists have sought to transmute elements, the most famous example being the long quest to turn lead into gold. Transmutation has been realized in modern times, but on a minute scale using a massive particle accelerator.

Now, theorists at Princeton University have proposed a different approach to this ancient ambition — just make one material behave like another. A computational theory published Feb. 24 [2017] in the journal Physical Review Letters (“How to Make Distinct Dynamical Systems Appear Spectrally Identical”) demonstrates that any two systems can be made to look alike, even if just for the smallest fraction of a second.

In this context, for two objects to “look” like each other, they need to reflect light in the same way. The Princeton researchers’ method involves using light to make non-permanent changes to a substance’s molecules so that they mimic the reflective properties of another substance’s molecules. This ability could have implications for optical computing, a type of computing in which electrons are replaced by photons that could greatly enhance processing power but has proven extremely difficult to engineer. It also could be applied to molecular detection and experiments in which expensive samples could be replaced by cheaper alternatives.

A Feb. 28, 2017 Princeton University news release (also on EurekAlert) by Tien Nguyen, which originated the news item, expands on the theme (Note: Links have been removed),

“It was a big shock for us that such a general statement as ‘any two objects can be made to look alike’ could be made,” said co-author Denys Bondar, an associate research scholar in the laboratory of co-author Herschel Rabitz, Princeton’s Charles Phelps Smyth ’16 *17 Professor of Chemistry.

The Princeton researchers posited that they could control the light that bounces off a molecule or any substance by controlling the light shone on it, which would allow them to alter how it looks. This type of manipulation requires a powerful light source such as an ultrafast laser and would last for only a femtosecond, or one quadrillionth of a second. Unlike normal light sources, this ultrafast laser pulse is strong enough to interact with molecules and distort their electron cloud while not actually changing their identity.

“The light emitted by a molecule depends on the shape of its electron cloud, which can be sculptured by modern lasers,” Bondar said. Using advanced computational theory, the research team developed a method called “spectral dynamic mimicry” that allowed them to calculate the laser pulse shape, which includes timing and wavelength, to produce any desired spectral output. In other words, making any two systems look alike.

Conversely, this spectral control could also be used to make two systems look as different from one another as possible. This differentiation, the researchers suggested, could prove valuable for applications of molecular detections such as identifying toxic versus safe chemicals.

Shaul Mukamel, a chemistry professor at the University of California-Irvine, said that the Princeton research is a step forward in an important and active research field called coherent control, in which light can be manipulated to control behavior at the molecular level. Mukamel, who has collaborated with the Rabitz lab but was not involved in the current work, said that the Rabitz group has had a prominent role in this field for decades, advancing technology such as quantum computing and using light to drive artificial chemical reactivity.

“It’s a very general and nice application of coherent control,” Mukamel said. “It demonstrates that you can, by shaping the optical paths, bring the molecules to do things that you want beforehand — it could potentially be very significant.”

Since the Middle Ages, alchemists have sought to transmute elements, the most famous example being the long quest to turn lead into gold. Now, theorists at Princeton University have proposed a different approach to this ancient ambition — just make one material behave like another, even if just for the smallest fraction of a second. The researchers are, left to right, Renan Cabrera, an associate research scholar in chemistry; Herschel Rabitz, Princeton’s Charles Phelps Smyth ’16 *17 Professor of Chemistry; associate research scholar in chemistry Denys Bondar; and graduate student Andre Campos. (Photo by C. Todd Reichart, Department of Chemistry)

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

How to Make Distinct Dynamical Systems Appear Spectrally Identical by
Andre G. Campos, Denys I. Bondar, Renan Cabrera, and Herschel A. Rabitz.
Phys. Rev. Lett. 118, 083201 (Vol. 118, Iss. 8) DOI:https://doi.org/10.1103/PhysRevLett.118.083201 Published 24 February 2017

© 2017 American Physical Society

This paper is behind a paywall.

Scientifica radio

Scientifica Radio, a CKUT.ca (Montréal McGill [University] Campus Community Radio) radio science magazine has been broadcasting since October 2016. Episode 11 features a series of interviews held at the American Association for the Advancement of Science (AAAS) 2017 annual meeting held Feb. 16, – 20, 2017 in Boston, Massachusetts. From the Episode 11 webpage (Note: A link has been removed),

On today’s [Feb. 24, 2017] episode, Bethany Wong follows Brïte Pauchet as she head [sic] to Boston to cover the annual meeting of the American Association for the Advancement of Science  (AAAS). This is one of the world’s largest general scientific conferences, bringing together researchers, science communicators, policy makers and educators from around the world.

Brite Pauchet writes and publishes the Brite Sciences blog. Her blog, where I found the reference to Scientifica Radio, is written in French but the version of Episode 11 I’ve linked to is in English.

Peripheral nerves (a rat’s) regenerated when wrapped with nanomesh fiber

A Feb.28,2017 news item on Nanowerk announces a proposed nerve regeneration technique (Note: A link has been removed),

A research team consisting of Mitsuhiro Ebara, MANA associate principal investigator, Mechanobiology Group, NIMS, and Hiroyuki Tanaka, assistant professor, Orthopaedic Surgery, Osaka University Graduate School of Medicine, developed a mesh which can be wrapped around injured peripheral nerves to facilitate their regeneration and restore their functions (Acta Biomaterialia, “Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model”).

This mesh incorporates vitamin B12—a substance vital to the normal functioning of nervous systems—which is very soft and degrades in the body. When the mesh was applied to injured sciatic nerves in rats, it promoted nerve regeneration and recovery of their motor and sensory functions.

A Feb. 27, 2017 Japan National Institute for Materials Science (NIMS) press release for Osaka University, which originated the news item, provides more detail,

Artificial nerve conduits have been developed in the past to treat peripheral nerve injuries, but they merely form a cross-link to the injury site and do not promote faster nerve regeneration. Moreover, their application is limited to relatively few patients suffering from a complete loss of nerve continuity. Vitamin B12 has been known to facilitate nerve regeneration, but oral administration of it has not proven to be very effective, and no devices capable of delivering vitamin B12 directly to affected sites had been available. Therefore, it had been hoped to develop such medical devices to actively promote nerve regeneration in the many patients who suffer from nerve injuries but have not lost nerve continuity.

The NIMS-Osaka University joint research team recently developed a special mesh that can be wrapped around an injured nerve which releases vitamin B12 (methylcobalamin) until the injury heals. By developing very fine mesh fibers (several hundred nanometers in diameter) and reducing the crystallinity of the fibers, the team successfully created a very soft mesh that can be wrapped around a nerve. This mesh is made of a biodegradable plastic which, when implanted in animals, is eventually eliminated from the body. In fact, experiments demonstrated that application of the mesh directly to injured sciatic nerves in rats resulted in regeneration of axons and recovery of motor and sensory functions within six weeks.

The team is currently negotiating with a pharmaceutical company and other organizations to jointly study clinical application of the mesh as a medical device to treat peripheral nerve disorders, such as CTS.

This study was supported by the JSPS KAKENHI program (Grant Number JP15K10405) and AMED’s Project for Japan Translational and Clinical Research Core Centers (also known as Translational Research Network Program).

Figure 1. Conceptual diagram showing a nanofiber mesh incorporating vitamin B12 and its application to treat a peripheral nerve injury.

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

Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model by Koji Suzuki, Hiroyuki Tanaka, Mitsuhiro Ebara, Koichiro Uto, Hozo Matsuoka, Shunsuke Nishimoto, Kiyoshi Okada, Tsuyoshi Murase, Hideki Yoshikawa. Acta Biomaterialia http://dx.doi.org/10.1016/j.actbio.2017.02.004 Available online 5 February 2017

This paper is behind a paywall.

Canada’s strength in regenerative medicine

Urgh! I will scream if I see the phrase “Canada punches above its weight” or some variant thereof one more time. Please! Stop the madness! The latest culprit is the Canadian Council of Academies in the title for its March 9, 2017 news release on EurekAlert,

Canada continues to punch above its weight in the field of regenerative medicine

A new workshop report, Building on Canada’s Strengths in Regenerative Medicine, released today [March 9, 2017] by the Council of Canadian Academies (CCA), confirms that Canadian researchers continue to be recognized as scientific leaders in the field of regenerative medicine and stem cell science.

“Overall, the evidence shows that Canadian research in regenerative medicine continues to be strong,” said Dr. Janet Rossant, FRSC, Chair of the Workshop Steering Committee and President and Scientific Director of the Gairdner Foundation. “While Canadian research is both of high quality and highly cited, it is our collaborative culture, enhanced by our national networks that keeps Canada leading in this field.”

Since the discovery of stem cells in the early 1960s by Canadian scientists Drs. James Till and Ernest McCulloch, significant advancements in regenerative medicine have followed, many by Canadian researchers and practitioners. The appeal of regenerative medicine lies in its curative approach. It replaces or regenerates human cells, tissues, or organs to restore or establish normal function using stem cells. A well-known example of regenerative medicine is the use of bone marrow transplants for leukemia. Although Canada has been historically strong in the field of regenerative medicine, experts caution that we must not lose momentum.

“Canada has been a leader in the field of regenerative medicine for decades, but maintaining this excellence requires ongoing efforts including continued stable and strategic investment in researchers, collaborative networks, and infrastructure,” Dr. Rossant notes. “Several countries are investing heavily in regenerative medicine and stem cell science. Canada has a real opportunity to stay ahead of the curve and remain at the forefront of this field, but it will require us to harness key opportunities now.” [emphasis mine]

The workshop report identifies several opportunities to strengthen the regenerative medicine community in Canada. Opportunities identified as particularly promising focus on:

* formalizing the coordination among regenerative medicine initiatives and key players to speak with one voice on common priorities;

* establishing long-term and stable support for current networks, including those focused on commercialization, to help address the so-called “valley of death” that exists when translating research discoveries to clinical and industry settings;

* enhancing coordination and alignment between the federal regulatory system and provincial healthcare systems; and

* supporting existing manufacturing infrastructure and growing the regenerative medicine industry in Canada to provide jobs for highly-skilled personnel while also benefiting the Canadian economy.

The workshop participants also considered several specific opportunities such as:

* enhancing coordination of Canada’s regenerative medicine clinical trial sites to enable sharing of best practices related to funding, design, and recruitment;

* continued support for cross-training programs to ensure future generations of Canadian researchers have wide-ranging skills suited to the multidisciplinary nature of regenerative medicine;

* new incentives that encourage partnerships between research institutions and industry; and

* increasing efforts related to public engagement and outreach.

“Sometimes becoming excellent is easier than maintaining excellence,” said Dr. Eric M. Meslin, FCAHS, President and CEO of the Council of Canadian Academies. “This is why taking stock of Canada’s place in the regenerative medicine landscape at a point in time is important, especially where the science is moving quickly; it helps those in the field understand the opportunities and will contribute to the ongoing policy discussion in Canada.”

This report was released a few weeks in advance of the federal budget (due tomorrow Wednesday, March 22, 2017). That’s a coincidence, yes?  Interestingly, the 2017 iteration is supposed to be an ‘innovation’ budget, i.e.. designed to stimulate the tech sector if a March 20, 2017 article by David Cochrane for CBC (Canadian Broadcasting Corporation) news online is to be believed. Nowhere in the article is there any mention of regenerative medicine or science, for that matter.

You can download the full report (60 pp.) from the Building on Canada’s Strengths in Regenerative Medicine webpage on the CCA website.

Do your physical therapy and act as a citizen scientist at the same time

I gather that recovering from a serious injury and/or surgery can require exercise regimens which help strengthen you but can be mind-numbingly boring. According to a Feb. 23, 30217 New York University Tandon School of Engineering news release (also on EurekAlert), scientists have found a way to make the physical rehabilitation process more meaningful,

Researchers at the NYU Tandon School of Engineering have devised a method by which patients requiring repetitive rehabilitative exercises, such as those prescribed by physical therapists, can voluntarily contribute to scientific projects in which massive data collection and analysis is needed.

Citizen science empowers people with little to no scientific training to participate in research led by professional scientists in different ways. The benefit of such an activity is often bidirectional, whereby professional scientists leverage the effort of a large number of volunteers in data collection or analysis, while the volunteers increase their knowledge on the topic of the scientific endeavor. Tandon researchers added the benefit of performing what can sometimes be boring or painful exercise regimes in a more appealing yet still therapeutic manner.

The citizen science activity they employed entailed the environmental mapping of a polluted body of water (in this case Brooklyn’s Gowanus Canal) with a miniature instrumented boat, which was remotely controlled by the participants through their physical gestures, as tracked by a low-cost motion capture system that does not require the subject to don special equipment. The researchers demonstrated that the natural user interface offers an engaging and effective means for performing environmental monitoring tasks. At the same time, the citizen science activity increased the commitment of the participants, leading to a better motion performance, quantified through an array of objective indices.

Visiting Researcher Eduardo Palermo (of Sapienza University of Rome), Post-doctoral Researcher Jeffrey Laut, Professor of Technology Management and Innovation Oded Nov, late Research Professor Paolo Cappa, and Professor of Mechanical and Aerospace Engineering Maurizio Porfiri provided subjects with a Microsoft Kinect sensor, a markerless human motion tracker capable of estimating three-dimensional coordinates of human joints that was initially designed for gaming but has since been widely repurposed as an input device for natural user interfaces. They asked participants to pilot the boat, controlling thruster speed and steering angle, by lifting one arm away from the trunk and using wrist motions, in effect, mimicking one widely adopted type of rehabilitative exercises based on repetitively performing simple movements with the affected arm. Their results suggest that an inexpensive, off-the-shelf device can offer an engaging means to contribute to important scientific tasks while delivering relevant and efficient physical exercises.

“The study constitutes a first and necessary step toward rehabilitative treatments of the upper limb through citizen science and low-cost markerless optical systems,” Porfiri explains. “Our methodology expands behavioral rehabilitation by providing an engaging and fun natural user interface, a tangible scientific contribution, and an attractive low-cost markerless technology for human motion capture.”

Caption: NYU Tandon researchers reported that volunteers who performed repetitive exercises while contributing as citizen scientists were more effective in their physical therapy motions. In the experiment, the volunteers controlled a small boat monitoring the polluted Gowanus Canal by performing hand and arm motions using the Microsoft Kinect motion capture system. Credit: NYU Tandon, PLoS ONE

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

A Natural User Interface to Integrate Citizen Science and Physical Exercise by Eduardo Palermo, Jeffrey Laut, Oded Nov, Paolo Cappa, Maurizio Porfiri. Public Library of Science (PLoS) http://dx.doi.org/10.1371/journal.pone.0172587 Published: February 23, 2017

This paper is open access.

Bidirectional prosthetic-brain communication with light?

The possibility of not only being able to make a prosthetic that allows a tetraplegic to grab a coffee but to feel that coffee  cup with their ‘hand’ is one step closer to reality according to a Feb. 22, 2017 news item on ScienceDaily,

Since the early seventies, scientists have been developing brain-machine interfaces; the main application being the use of neural prosthesis in paralyzed patients or amputees. A prosthetic limb directly controlled by brain activity can partially recover the lost motor function. This is achieved by decoding neuronal activity recorded with electrodes and translating it into robotic movements. Such systems however have limited precision due to the absence of sensory feedback from the artificial limb. Neuroscientists at the University of Geneva (UNIGE), Switzerland, asked whether it was possible to transmit this missing sensation back to the brain by stimulating neural activity in the cortex. They discovered that not only was it possible to create an artificial sensation of neuroprosthetic movements, but that the underlying learning process occurs very rapidly. These findings, published in the scientific journal Neuron, were obtained by resorting to modern imaging and optical stimulation tools, offering an innovative alternative to the classical electrode approach.

A Feb. 22, 2017 Université de Genève press release on EurekAlert, which originated the news item, provides more detail,

Motor function is at the heart of all behavior and allows us to interact with the world. Therefore, replacing a lost limb with a robotic prosthesis is the subject of much research, yet successful outcomes are rare. Why is that? Until this moment, brain-machine interfaces are operated by relying largely on visual perception: the robotic arm is controlled by looking at it. The direct flow of information between the brain and the machine remains thus unidirectional. However, movement perception is not only based on vision but mostly on proprioception, the sensation of where the limb is located in space. “We have therefore asked whether it was possible to establish a bidirectional communication in a brain-machine interface: to simultaneously read out neural activity, translate it into prosthetic movement and reinject sensory feedback of this movement back in the brain”, explains Daniel Huber, professor in the Department of Basic Neurosciences of the Faculty of Medicine at UNIGE.

Providing artificial sensations of prosthetic movements

In contrast to invasive approaches using electrodes, Daniel Huber’s team specializes in optical techniques for imaging and stimulating brain activity. Using a method called two-photon microscopy, they routinely measure the activity of hundreds of neurons with single cell resolution. “We wanted to test whether mice could learn to control a neural prosthesis by relying uniquely on an artificial sensory feedback signal”, explains Mario Prsa, researcher at UNIGE and the first author of the study. “We imaged neural activity in the motor cortex. When the mouse activated a specific neuron, the one chosen for neuroprosthetic control, we simultaneously applied stimulation proportional to this activity to the sensory cortex using blue light”. Indeed, neurons of the sensory cortex were rendered photosensitive to this light, allowing them to be activated by a series of optical flashes and thus integrate the artificial sensory feedback signal. The mouse was rewarded upon every above-threshold activation, and 20 minutes later, once the association learned, the rodent was able to more frequently generate the correct neuronal activity.

This means that the artificial sensation was not only perceived, but that it was successfully integrated as a feedback of the prosthetic movement. In this manner, the brain-machine interface functions bidirectionally. The Geneva researchers think that the reason why this fabricated sensation is so rapidly assimilated is because it most likely taps into very basic brain functions. Feeling the position of our limbs occurs automatically, without much thought and probably reflects fundamental neural circuit mechanisms. This type of bidirectional interface might allow in the future more precisely displacing robotic arms, feeling touched objects or perceiving the necessary force to grasp them.

At present, the neuroscientists at UNIGE are examining how to produce a more efficient sensory feedback. They are currently capable of doing it for a single movement, but is it also possible to provide multiple feedback channels in parallel? This research sets the groundwork for developing a new generation of more precise, bidirectional neural prostheses.

Towards better understanding the neural mechanisms of neuroprosthetic control

By resorting to modern imaging tools, hundreds of neurons in the surrounding area could also be observed as the mouse learned the neuroprosthetic task. “We know that millions of neural connections exist. However, we discovered that the animal activated only the one neuron chosen for controlling the prosthetic action, and did not recruit any of the neighbouring neurons”, adds Daniel Huber. “This is a very interesting finding since it reveals that the brain can home in on and specifically control the activity of just one single neuron”. Researchers can potentially exploit this knowledge to not only develop more stable and precise decoding techniques, but also gain a better understanding of most basic neural circuit functions. It remains to be discovered what mechanisms are involved in routing signals to the uniquely activated neuron.

Caption: A novel optical brain-machine interface allows bidirectional communication with the brain. While a robotic arm is controlled by neuronal activity recorded with optical imaging (red laser), the position of the arm is fed back to the brain via optical microstimulation (blue laser). Credit: © Daniel Huber, UNIGE

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

Rapid Integration of Artificial Sensory Feedback during Operant Conditioning of Motor Cortex Neurons by Mario Prsa, Gregorio L. Galiñanes, Daniel Huber. Neuron Volume 93, Issue 4, p929–939.e6, 22 February 2017 DOI: http://dx.doi.org/10.1016/j.neuron.2017.01.023 Open access funded by European Research Council

This paper is open access.

The inside scoop on beetle exoskeletons

In the past I’ve covered work on the Namib beetle and its bumps which allow it to access condensation from the air in one of the hottest places on earth and work on jewel beetles and how their structural colo(u)r is derived. Now, there’s research into a beetle’s body armor from the University of Nebraska-Lincoln according to a Feb. 22, 2017 news item on ScienceDaily,

Beetles wear a body armor that should weigh them down — think medieval knights and turtles. In fact, those hard shells protecting delicate wings are surprisingly light, allowing even flight.

Better understanding the structure and properties of beetle exoskeletons could help scientists engineer lighter, stronger materials. Such materials could, for example, reduce gas-guzzling drag in vehicles and airplanes and reduce the weight of armor, lightening the load for the 21st-century knight.

But revealing exoskeleton architecture at the nanoscale has proven difficult. Nebraska’s Ruiguo Yang, assistant professor of mechanical and materials engineering, and his colleagues found a way to analyze the fibrous nanostructure. …

A Feb. 22, 2017 University of Nebraska-Lincoln news release by Gillian Klucas (also on EurekAlert), which originated the news item, describes skeletons and the work in more detail,

The lightweight exoskeleton is composed of chitin fibers just around 20 nanometers in diameter (a human hair measures approximately 75,000 nanometers in diameter) and packed and piled into layers that twist in a spiral, like a spiral staircase. The small diameter and helical twisting, known as Bouligand, make the structure difficult to analyze.

Yang and his team developed a method of slicing down the spiral to reveal a surface of cross-sections of fibers at different orientations. From that viewpoint, the researchers were able to analyze the fibers’ mechanical properties with the aid of an atomic force microscope. This type of microscope applies a tiny force to a test sample, deforms the sample and monitors the sample’s response. Combining the experimental procedure and theoretical analysis, the researchers were able to reveal the nanoscale architecture of the exoskeleton and the material properties of the nanofibers.

Yang holds a piece of the atomic force microscope used to measure the beetle's surface. A small wire can barely be seen in the middle of the piece. Unseen is a two-nano-size probe attached to the wire, which does the actual measuring.

Craig Chandler | University Communication

Yang holds a piece of the atomic force microscope used to measure the beetle’s surface. A small wire can barely be seen in the middle of the piece. Unseen is a two-nano-size probe attached to the wire, which does the actual measuring.

They made their discoveries in the common figeater beetle, Cotinis mutabilis, a metallic green native of the western United States. But the technique can be used on other beetles and hard-shelled creatures and might also extend to artificial materials with fibrous structures, Yang said.

Comparing beetles with differing demands on their exoskeletons, such as defending against predators or environmental damage, could lead to evolutionary insights as well as a better understanding of the relationship between structural features and their properties.

Yang’s co-authors are Alireza Zaheri and Horacio Espinosa of Northwestern University; Wei Gao of the University of Texas at San Antonio; and Cheryl Hayashi of the University of California, Riverside.

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

Exoskeletons: AFM Identification of Beetle Exocuticle: Bouligand Structure and Nanofiber Anisotropic Elastic Properties by Ruiguo Yang, Alireza Zaheri,Wei Gao, Charely Hayashi, Horacio D. Espinosa. Adv. Funct. Mater. vol. 27 (6) 2017 DOI: 10.1002/adfm.201770031 First published: 8 February 2017

This paper is behind a paywall.

The Imagineers of War: The Untold Story of DARPA, the Pentagon Agency That Changed the World on March 21, 2017 at the Woodrow Wilson International Center for Scholars

I received a March 17, 2017 Woodrow Wilson International Center for Scholars notice (via email) about this upcoming event,

The Imagineers of War: The Untold Story of DARPA [Defense Advanced Research Projects Agency], the Pentagon Agency That Changed the World

There will be a webcast of this event

In The Imagineers of War, Weinberger gives us a definitive history of the agency that has quietly shaped war and technology for nearly 60 years. Founded in 1958 in response to the launch of Sputnik, DARPA’s original mission was to create “the unimagined weapons of the future.” Over the decades, DARPA has been responsible for countless inventions and technologies that extend well beyond military technology.

Weinberger has interviewed more than one hundred former Pentagon officials and scientists involved in DARPA’s projects—many of whom have never spoken publicly about their work with the agency—and pored over countless declassified records from archives around the country, documents obtained under the Freedom of Information Act, and exclusive materials provided by sources. The Imagineers of War is a compelling and groundbreaking history in which science, technology, and politics collide.

Speakers


  • Sharon Weinberger

    Global Fellow
    Author, Imagineers of War, National Security Editor at The Intercept and former Wilson Center Fellow

  • Richard Whittle

    Global Fellow
    Author, Predator: The Secret Origins of the Drone Revolution and Wilson Center Global Fellow

The logistics:

6th Floor, Woodrow Wilson Center

I first heard about DARPA in reference to the internet. A developer I was working with noted that ARPA (DARPA’s predecessor agency) was instrumental in the development of the internet.

You can register for the event here. Should you be interested in the webcast, you can check this page.

As a point of interest, the Wilson Center (also known as the Woodrow Wilson International Center for Scholars) is one of the independent agencies slated to be defunded in the 2017 US budget as proposed by President Donald Trump according to a March 16, 2017 article by Elaine Godfrey for The Atlantic.