Lifeboat Foundation

Researchers have developed artificial ‘chameleon skin’ that changes color when exposed to light and could be used in applications such as active camouflage and large-scale dynamic displays.

The material, developed by researchers from the University of Cambridge, is made of tiny particles of gold coated in a polymer shell, and then squeezed into microdroplets of water in oil. When exposed to heat or light, the particles stick together, changing the color of the material. The results are reported in the journal Advanced Optical Materials.

In nature, animals such as chameleons and cuttlefish are able to change color thanks to chromatophores: skin cells with contractile fibers that move pigments around. The pigments are spread out to show their color, or squeezed together to make the cell clear.

We can probably all agree on one thing: that technological gadgets are becoming smaller and smaller by the day. Now, contact lenses are getting smarter – well soon – and all thanks to nanotechnology.

Thin, flexible fibers made of carbon nanotubes have now proven able to bridge damaged heart tissues and deliver the electrical signals needed to keep those hearts beating.

Scientists at Texas Heart Institute (THI) report they have used those biocompatible fibers in studies that showed sewing them directly into damaged tissue can restore electrical function to hearts.

“Instead of shocking and defibrillating, we are actually correcting diseased conduction of the largest major pumping chamber of the heart by creating a bridge to bypass and conduct over a scarred area of a damaged heart,” said Dr. Mehdi Razavi, a cardiologist and director of Electrophysiology Clinical Research and Innovations at THI, who co-led the study with Rice chemical and biomolecular engineer Matteo Pasquali.

At human scale, controlling temperature is a straightforward concept. Turtles sun themselves to keep warm. To cool a pie fresh from the oven, place it on a room-temperature countertop.

At the nanoscale—at distances less than 1/100th the width of the thinnest human hair—controlling temperature is much more difficult. Nanoscale distances are so small that objects easily become thermally coupled: If one object heats up to a certain temperature, so does its neighbor.

When scientists use a beam of light as that heat source, there is an additional challenge: Thanks to heat diffusion, materials in the beam path heat up to approximately the same temperature, making it difficult to manipulate the thermal profiles of objects within the beam. Scientists have never been able to use light alone to actively shape and control thermal landscapes at the nanoscale.

Researchers have developed a soft neural implant that can be wirelessly controlled using a smartphone. It is the first wireless neural device capable of indefinitely delivering multiple drugs and multiple colour lights, which neuroscientists believe can speed up efforts to uncover brain diseases such as Parkinson’s, Alzheimer’s, addiction, depression, and pain. A team under Professor Jae-Woong Jeong from the School of Electrical Engineering at KAIST and his collaborators have invented a device that can control neural circuits using a tiny brain implant controlled by a smartphone. The device, using Lego-like replaceable drug cartridges and powerful, low-energy Bluetooth, can target specific neurons of interest using drugs and light for prolonged periods. This study was published in Nature Biomedical Engineering.

“This novel device is the fruit of advanced electronics design and powerful micro and nanoscale engineering,” explained Professor Jeong. “We are interested in further developing this technology to make a brain implant for clinical applications.”

A KAIST team has designed a novel strategy for synthesizing single-crystalline graphene quantum dots, which emit stable blue light. The research team confirmed that a display made of their synthesized graphene quantum dots successfully emitted blue light with stable electric pressure, reportedly resolving the long-standing challenges of blue light emission in manufactured displays. The study, led by Professor O Ok Park in the Department of Chemical and Biological Engineering, was featured online in Nano Letters on July 5.

Graphene has gained increased attention as a next-generation material for its heat and electrical conductivity as well as its transparency. However, single and multi-layered graphene have characteristics of a conductor so that it is difficult to apply into semiconductor. Only when downsized to the nanoscale, semiconductor’s distinct feature of bandgap will be exhibited to emit the light in the graphene. This illuminating featuring of dot is referred to as a graphene quantum dot.

Conventionally, single-crystalline graphene has been fabricated by chemical vapor deposition (CVD) on copper or nickel thin films, or by peeling graphite physically and chemically. However, graphene made via chemical vapor deposition is mainly used for large-surface transparent electrodes. Meanwhile, graphene made by chemical and physical peeling carries uneven size defects.

ISN research is organized into three Strategic Research Areas (SRAs), representing the most fundamental subject areas for scientific inquiry at the Institute. SRAs are designed to address broad strategic challenges facing the Soldier, and are subdivided into specific Projects.

The phrase “positive reinforcement,” is something you hear more often in an article about child rearing than one about artificial intelligence. But according to Alice Parker, Dean’s Professor of Electrical Engineering in the Ming Hsieh Department of Electrical and Computer Engineering, a little positive reinforcement is just what our AI machines need. Parker has been building electronic circuits for over a decade to reverse-engineer the human brain to better understand how it works and ultimately build artificial systems that mimic it. Her most recent paper, co-authored with Ph.D. student Kun Yue and colleagues from UC Riverside, was just published in the journal Science Advances and takes an important step towards that ultimate goal.

The AI we rely on and read about today is modeled on traditional computers; it sees the world through the lens of binary zeros and ones. This is fine for making complex calculations but, according to Parker and Yue, we’re quickly approaching the limits of the size and complexity of problems we can solve with the platforms our AI exists on. “Since the initial deep learning revolution, the goals and progress of deep-learning based AI as we know it has been very slow,” Yue says. To reach its full potential, AI can’t simply think better—it must react and learn on its own to events in real time. And for that to happen, a massive shift in how we build AI in the first place must be conceived.

To address this problem, Parker and her colleagues are looking to the most accomplished learning system nature has ever created: the human brain. This is where positive reinforcement comes into play. Brains, unlike computers, are analog learners and biological memory has persistence. Analog signals can have multiple states (much like humans). While a binary AI built with similar types of nanotechnologies to achieve long-lasting memory might be able to understand something as good or bad, an analog brain can understand more deeply that a situation might be “very good,” “just okay,” “bad” or “very bad.” This field is called neuromorphic computing and it may just represent the future of artificial intelligence.

This week’s podcast features an interview with Ray LaPierre, who heads up the department of engineering physics at McMaster University in Canada. Ray talks to fellow Canadian Hamish Johnston about his research in semiconductor nanowires, in particular for use in photonics and quantum computers, and also shares his experiences of working at JDS Uniphase during the telecoms boom.

Physics World’s Anna Demming also joins the podcast to describe a flurry of new results in the emerging field of twistronics – where two layers of graphene are stacked on top of each other but twisted at a slight angle to each other. The discovery last year that bilayer graphene can become a superconductor if the two graphene layers are twisted at the so-called magic angle of 1.1º won Physics World’s 2018 Breakthrough of the Year, and since then the race has been on to investigate other angle-dependent properties of twisted bilayer graphene. Anna describes how different research teams are now trying to work out what causes these intriguing effects.

We also talk to industry editor Margaret Harris about the importance of technology and engineering for scientific progress. Margaret shares her own “light-bulb” moment, when she realized that new laser technology could have saved hours of experimental time during her PhD, and also highlights several articles in the latest Physics World Focus on Instruments and Vacuum that highlight how breakthrough scientific discoveries rely on developments in the enabling technologies – including the first images of a black hole that were revealed in April.