Articles from December 2014

Smart Skin For Robots Simulating Sense Of Touch

It’s soft, warm, and can sense pressure, heat and humidity – just like human skin. This is ‘smartartificial skin and it’s the first to simulate the sense of touch. Its developers at South Korea’s Seoul National University say they aimed to create a material as close to human skin as possible.
prosthetic smart skin
We developed the synthetic skin which has the sense of feeling that exactly copies human skin. The skin can feel pressure, temperature, strain, humidity. Also it is soft, just like human skin, and embedded with heating elements that can make itself warm,” says Professor Kim Dae-Hong from the School of Chemical and Biological Engineering at Seoul National University. The warm prosthetic skin matches the temperature of the human body. And its layers give it its sense of touch.
The bottom layer of skin is rubbery material that can express the softness of human skin. Above the rubber layer, there is ultra thin polyimide and then silicon, which acts as sensors“, he adds. Researchers have combined their stretchy skin with a prosthetic hand and found it can be used for complex operations. Hand-shaking, keyboard-tapping and ball-grasping are all possible. And its humidity sensors mean it can even tell the difference between a dry diaper and a wet one. The researchers hope the ultra-thin skin will be able to send sensory signals to the brain. At the moment, this has only been demonstrated in small animals. But Professor Kim has high hopes for the future of his team’s prosthetic skin: “I hope a robotic limb with this synthetic skin can be used by disabled people. For industrial uses, it can be applied to various types of robots, like a humanoid robot“, he says. The developers envisage the synthetic skin being used by amputees. But a diaper-changing robot could also come in handy.

Artificial Protein Carries Atoms Across Membranes

Human cells are protected by a largely impenetrable molecular membrane. Now Gevorg Grigoryan, an assistant professor of computer science at Dartmouth College, and researchers from other institutions have built the first artificial transporter protein that carries individual atoms across membranes, opening the possibility of engineering a new class of smart molecules with applications in fields as wide ranging as nanotechnology and medicine.

transport protein 2
Each human cell is surrounded by a lipid membrane, a molecular barrier that serves to contain the cellular machinery and protect it from the surrounding elements. This cellular “skin” is impenetrable to most biological molecules but also presents a conundrum: if chemicals can’t get in or out, how is a cell to receive nutrients (food) and remove unwanted products of metabolism (trash)?

Nature has come up with an elegant solution to this logistical problem — transporter proteins (or transporters). These molecular machines are embedded in the cellular membrane and serve as gatekeepers, allowing specific chemicals to shuttle in and out when needed. Though biologists have known about transporters for many decades, their precise mechanism of action has been elusive.

The study, which has been published in the journal Science, is a milestone in designing and understanding membrane proteins (a PDF is available upon request). The study was conducted by researchers from Dartmouth College, the University of California-San Francisco, Massachusetts Institute of Technology and National Institute of Science Educational and Research in India.


Send Men Above Venus, NASA ‘s New Dream

To send an astronauts team around Venus is easier than to Mars. Why? Mainly because Venus is much closer to the Sun and due to continuous progress in the solar panel technology, any spaceship will benefit from an inexhaustible source of solar energy. The atmosphere of Venus is, as well, an exciting destination for both further scientific study and future human exploration. A lighter-than-air vehicle can carry either a host of instruments and probes, or a habitat and ascent vehicle for a crew of two astronauts to explore Venus for up to a month. The mission requires less time to complete than a crewed Mars mission, and the environment at 50 km is relatively benign, with similar pressure, density, gravity, and radiation protection to the surface of Earth. A recent internal NASA study of a High Altitude Venus Operational Concept (HAVOC) led to the development of an evolutionary program for the exploration of Venus, with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus’s atmosphere.
NASA_HAVOCKey technical challenges for the mission include performing the aerocapture maneuvers at Venus and Earth, inserting and inflating the airship at Venus, and protecting the solar panels and structure from the sulfuric acid in the atmosphere. With advances in technology and further refinement of the concept, missions to the Venusian atmosphere can expand humanity’s future in space.


Nano Filters Clean Dirty Industry

Prototypes of nano-cellulose based filters with high purification capacity towards environmentally hazardous contaminants from industrial effluents eg. process industries, have been developed by researchers at Luleå University of Technology (Sweden). The research, conducted in collaboration with Imperial College in the UK has reached a breakthrough with the prototypes and they will now be tested on a few industries in Europe.

– The bio-based filter of nano-cellulose is to be used for the first time in real-life situations and tested within a process industry and in municipal wastewater treatment in Spain. Other industries have also shown interest in this technology and representatives of the mining industry have contacted me and I have even received requests from a large retail chain in the UK, says Aji Mathew Associate Professor, Division of Materials Science at Luleå University.
nano filter

Researchers have combined a cheap residue from the cellulose industry, with functional nano-cellulose to prepare adsorbent sheets with high filtration capacity. The sheets have since been constructed to different prototypes, called cartridges, to be tested. They have high capacity and can filter out heavy metal ions from industrial waters, dyes residues from the printing industry and nitrates from municipal water. Next year, larger sheets with a layer of nano-cellulose can be produced and formed into cartridges, with higher capacity.

– Each such membrane can be tailored to have different removal capability depending on the kind of pollutant, viz., copper, iron, silver, dyes, nitrates and the like.


How To Design New Materials With Simple Computer Simulations

Scientists from the University College London (UCL ) have shown how advanced computer simulations can be used to design new composite materials. Nanocomposites, which are widely used in industry, are revolutionary materials in which microscopic particles are dispersed through plastics. But their development until now has been largely by trial and error.
The ‘virtual lab’, developed using supercomputer simulations by UCL’s James Suter, Deren Groen and Peter Coveney greatly improves our understanding of how composite materials are built on a molecular level. They allow the properties of a new material to be predicted based simply on its structure and the way it is manufactured – a holy grail of materials science.

SuperComputer ARCHER
The ARCHER supercomputer, one of several used in this study

“Developing composite materials has been a bit of a trial-and-error process until now,” says James Suter (UCL Chemistry), the first author of the study. “It typically involves grinding and mixing the ingredients and hoping for the best. Of course we test the properties of the resulting materials, but our understanding of how they are structured and why they have the properties they have, is quite limited. Our work means we can now predict how a new nanocomposite will perform, based only on their chemical composition and processing conditions.


How To Detect Alzheimer’s Disease Early

No methods currently exist for the early detection of Alzheimer’s disease, which affects one out of nine people over the age of 65. Now, an interdisciplinary team of Northwestern University scientists and engineers has developed a noninvasive MRI (magnetic resonance imaging) approach that can detect the disease in a living animal. And it can do so at the earliest stages of the disease, well before typical Alzheimer’s symptoms appear.

Led by neuroscientist William L. Klein and materials scientist Vinayak P. Dravid, the research team developed an MRI probe that pairs a magnetic nanostructure (MNS) with an antibody that seeks out the amyloid beta brain toxins responsible for onset of the disease. The accumulated toxins, because of the associated magnetic nanostructures, show up as dark areas in MRI scans of the brain. This ability to detect the molecular toxins may one day enable scientists to both spot trouble early and better design drugs or therapies to combat and monitor the disease. And, while not the focus of the study, early evidence suggests the MRI probe improves memory, too, by binding to the toxins to render them “handcuffed” to do further damage.
Fluorescent amyloid beta oligomers (green), bound to cultured hippocampal neurons, were detected with greater than 90 percent accuracy by the magnetic nanostructure probe (red)
We have a new brain imaging method that can detect the toxin that leads to Alzheimer’s disease,” said Klein, who first identified the amyloid beta oligomer in 1998. He is a professor of neurobiology in the Weinberg College of Arts and Sciences. “Using MRI, we can see the toxins attached to neurons in the brain,” Klein said. “We expect to use this tool to detect this disease early and to help identify drugs that can effectively eliminate the toxin and improve health.

How To Purify Water

A new catalyst could have dramatic environmental benefits if it can live up to its potential, suggests research from Singapore. A*STAR researchers have produced a catalyst with gold-nanoparticle antennas that can improve water quality in daylight and also generate hydrogen as a green energy source. This water purification technology was developed by He-Kuan Luo, Andy Hor and colleagues from the A*STAR Institute of Materials Research and Engineering (IMRE).


Any innovative and benign technology that can remove or destroy organic pollutants from water under ambient conditions is highly welcome,” explains Hor, who is executive director of the IMRE and also affiliated with the National University of Singapore.

Photocatalytic materials harness sunlight to create electrical charges, which provide the energy needed to drive chemical reactions in molecules attached to the catalyst’s surface. In addition to decomposing harmful molecules in water, photocatalysts are used to split water into its components of oxygen and hydrogen; hydrogen can then be employed as a green energy source.
To demonstrate the efficiency of these catalysts, the researchers studied how they decomposed the dye rhodamine B in water. Within four hours of exposure to visible light 92 per cent of the dye was gone, which is much faster than conventional catalysts that lack gold nanoparticles.

RadioGenetics Remotely Control Cells, Genes

It’s the most basic of ways to find out what something does, whether it’s an unmarked circuit breaker or an unidentified geneflip its switch and see what happens. New remote-control technology may offer biologists a powerful way to do this with cells and genes. A team at Rockefeller University and Rensselaer Polytechnic Institute is developing a system that would make it possible to remotely control biological targets in living animals — rapidly, without wires, implants or drugs.
The team describes in the journal Nature Medicine, how it succeeded using electromagnetic waves to turn on insulin production to lower blood sugar in diabetic mice. Their system couples a natural iron storage particle, ferritin, to activate an ion channel called TRPV1 such that when the metal particle is exposed to a radio wave or magnetic field it opens the channel, leading to the activation of an insulin producing gene. Together, the two proteins act as a nano-machine that can be used to trigger gene expression in cells.

Tied together: Researchers experimented with different configurations for their remote control system, and they found the best relies on an iron nanoparticle (blue), which is tethered by a protein (green) to an ion channel (red). Above, all three appear within cell membranes.

The method allows one to wirelessly control the expression of genes in a living animal and could potentially be used for conditions like hemophilia to control the production of a missing protein. Two key attributes are that the system is genetically encoded and can activate cells remotely and quickly,” says Jeffrey Friedman, Marilyn M. Simpson Professor head of the Laboratory of Molecular Genetics at Rockefeller. “We are now exploring whether the method can also be used to control neural activity as a means for noninvasively modulating the activity of neural circuits.” Friedman and his Rensselaer colleague Jonathan S. Dordick were co-senior researchers on the project.


How To Harvest More of the Sun’s Energy

As solar panels become less expensive and capable of generating more power, solar energy is becoming a more commercially viable alternative source of electricity. However, the photovoltaic cells now used to turn sunlight into electricity can only absorb and use a small fraction of that light, and that means a significant amount of solar energy goes untapped.

A new technology created by researchers from Caltech, and described in a paper published online in Science Express, represents a first step toward harnessing that lost energy.

Sunlight is composed of many wavelengths of light. In a traditional solar panel, silicon atoms are struck by sunlight and the atoms’ outermost electrons absorb energy from some of these wavelengths of sunlight, causing the electrons to get excited. Once the excited electrons absorb enough energy to jump free from the silicon atoms, they can flow independently through the material to produce electricity. This is called the photovoltaic effect—a phenomenon that takes place in a solar panel‘s photovoltaic cells.

Although silicon-based photovoltaic cells can absorb light wavelengths that fall in the visible spectrum—light that is visible to the human eye—longer wavelengths such as infrared light pass through the silicon. These wavelengths of light pass right through the silicon and never get converted to electricity — and in the case of infrared, they are normally lost as unwanted heat.

An ultra-sensitive needle measures the voltage that is generated while the nanospheres are illuminated

The silicon absorbs only a certain fraction of the spectrum, and it’s transparent to the rest. If I put a photovoltaic module on my roof, the silicon absorbs that portion of the spectrum, and some of that light gets converted into power. But the rest of it ends up just heating up my roof,” says Harry A. Atwater, Professor of Applied Physics at the Resnick Sustainability Institute, who led the study. Now, Atwater and his colleagues have found a way to absorb and make use of these infrared waves with a structure composed not of silicon, but entirely of metal.

The new technique they’ve developed is based on a phenomenon observed in metallic structures known as plasmon resonance. Plasmons are coordinated waves, or ripples, of electrons that exist on the surfaces of metals at the point where the metal meets the air. While the plasmon resonances of metals are predetermined in nature, Atwater and his colleagues found that those resonances are capable of being tuned to other wavelengths when the metals are made into tiny nanostructures in the lab.

Normally in a metal like silver or copper or gold, the density of electrons in that metal is fixed; it’s just a property of the material,” Atwater says. “But in the lab, I can add electrons to the atoms of metal nanostructures and charge them up. And when I do that, the resonance frequency will change.”

We’ve demonstrated that these resonantly excited metal surfaces can produce a potential“—an effect very similar to rubbing a glass rod with a piece of fur: you deposit electrons on the glass rod. “You charge it up, or build up an electrostatic charge that can be discharged as a mild shock,” he says. “So similarly, exciting these metal nanostructures near their resonance charges up those metal structures, producing an electrostatic potential that you can measure.” This electrostatic potential is a first step in the creation of electricity, Atwater says. “If we can develop a way to produce a steady-state current, this could potentially be a power source.” He envisions a solar cell using the plasmoelectric effect someday being used in tandem with photovoltaic cells to harness both visible and infrared light for the creation of electricity.


Nano Sponges Cut Greenhouse Gases

In the fight against global warming, carbon capture – chemically trapping carbon dioxide before it releases into the atmosphere – is gaining momentum, but standard methods are plagued by toxicity, corrosiveness and inefficiency. Using a bag of chemistry tricks, Cornell materials scientists have invented low-toxicity, highly effective carbon-trapping “sponges” that could lead to increased use of the technology. A research team led by Emmanuel Giannelis, Professor of Engineering, has invented a powder that performs as well or better than industry benchmarks for carbon capture.
The researchers have been working on a better, safer carbon-capture method . Their latest consists of a silica scaffold, the sorbent support, with nanoscale pores for maximum surface area. They dip the scaffold into liquid amine, which soaks into the support like a sponge and partially hardens. The finished product is a stable, dry white powder that captures carbon dioxide even in the presence of moisture.

A scanning electron microscopy image of a pristine silica support, before the amine is added
We have made great strides in sustainability, particularly in the energy supply areas of alternative energy sources, and the demand side areas of energy conservation and building design standards,” KyuJung Whang, Cornell’s vice president for facilities services said.

A paper with their results, co-authored by postdoctoral associates Genggeng Qi and Liling Fu, appeared in Nature Communications.

Control Google Glass Directly By Your Mind

The british company This Place wants to change the future of usability for everyone. As a digital design agency, they are acutely aware of the importance of accessibility and potential for digital technologies to enhance the lives of millions of people who live with disabilities. In order to make a difference, the company focus on cutting out the need for a high level of dexterity to operate computers, and instead focus on utilising the power of the mind. Basically the device called MindRDR read brain waves in your mind.


Do you want to take a pic and to send it to your friends through Twitter? MindRDR will read the waves of your mind and operates the internet commands for you using your Google Glass.


Next step: control a computer remotely just with your mind, or just as you use an imaginary keyboard to control your computer

The mindRDR and the NeuroSky MindWave system could be great news for all humans stuck paralyzed in wheel chairs.


How To Make Drinking Water From Air Humidity

Understanding how a desert beetle harvests water from dew could help to improve drinking water collection in dew condensers mimicking the nanostructure of the beetle’s back

Insects are full of marvels—and this is certainly the case with a beetle from the Tenebrionind family, found in the extreme conditions of the Namib desert. Now, a team of scientists from ESPCI Paristech – France – has demonstrated that such insects can collect dew on their backs—and not just fog as previously thought. This is made possible by the wax nanostructure on the surface of the beetle’s elytra. These findings by José Guadarrama-Cetina,and colleagues were recently published in EPJ E. They bring us a step closer to harvesting dew to make drinking water from the humidity in the air. This, the team hopes, can be done by improving the water yield of man-made dew condensers that mimick the nanostructure on the beetle’s back.
desert beerle
It was not clear from previous studies whether water harvested by such beetles came from dew droplets, in addition to fog.

Guadarrama-Cetina and colleagues also performed an image analysis of dew drops forming on the insect’s back on the surface of the elytra, which appears as a series of bumps and valleys. Dew primarily forms in the valleys endowed with a hexagonal microstructure, they found, unlike the smooth surface of the bumps. This explains how drops can slide to the insect’s mouth when they reach a critical size.