Prof. Frank Gu, is a Canada Research Chair and Assistant Professor in the Department of Chemical Engineering at the University of Waterloo. He has established an interdisciplinary research program combining functional polymers and polymer-metal oxide hybrid materials to solve problems in medicine, agriculture and environmental protection.
Duke University engineers have developed a novel method for producing clean hydrogen, which could prove essential to weaning society off of fossil fuels and their environmental implications.
While hydrogen is ubiquitous in the environment, producing and collecting molecular hydrogen for transportation and industrial uses is expensive and complicated. Just as importantly, a byproduct of most current methods of producing hydrogen is carbon monoxide, which is toxic to humans and animals.
The Duke engineers, using a new catalytic approach, have shown in the laboratory that they can reduce carbon monoxide levels to nearly zero in the presence of hydrogen and the harmless byproducts of carbon dioxide and water. They also demonstrated that they could produce hydrogen by reforming fuel at much lower temperatures than conventional methods, which makes it a more practical option.
Catalysts are agents added to promote chemical reactions. In this case, the catalysts were nanoparticle combinations of gold and iron oxide (rust), but not in the traditional sense. Current methods depend on gold nanoparticles ability to drive the process as the sole catalyst, while the Duke researchers made both the iron oxide and the gold the focus of the catalytic process.
The study appears online in the May issue of the Journal of Catalysis, viewable at sciencedirect.com.
Another innovative feature has been added to the world’s first practical “artificial leaf,” making the device even more suitable for providing people in developing countries and remote areas with electricity, scientists reported here today. It gives the leaf the ability to self-heal damage that occurs during production of energy.
Daniel G. Nocera, Ph.D., described the advance during the “Kavli Foundation Innovations in Chemistry Lecture” at the 245th National Meeting & Exposition of the American Chemical Society, the world’s largest scientific society. About 14,000 scientists and others are expected for the meeting, which continues through Thursday with almost 12,000 reports on advances in science.
Nocera, leader of the research team, explained that the “leaf” mimics the ability of real leaves to produce energy from sunlight and water. The device, however, actually is a simple catalyst-coated wafer of silicon, rather than a complicated reproduction of the photosynthesis mechanism in real leaves. Dropped into a jar of water and exposed to sunlight, catalysts in the device break water down into its components, hydrogen and oxygen. Those gases bubble up and can be collected and used as fuel to produce electricity in fuel cells.
“Surprisingly, some of the catalysts we’ve developed for use in the artificial leaf device actually heal themselves,” Nocera said. “They are a kind of ‘living catalyst.’ This is an important innovation that eases one of the concerns about initial use of the leaf in developing countries and other remote areas.”
A Seattle-based startup, EnerG2, has developed a carbon anode that significantly improves the storage capacity of lithium-ion batteries without requiring a new battery design or a different manufacturing process.
Batteries with more energy density could allow electric vehicles to travel longer on a charge. They could also enable lighter, thinner electronic gadgets. Because of this, many advanced battery makers are pursuing a jump in storage capacity with novel chemistries and materials.
EnerG2 said last week that its synthetic carbon anode increases the storage capacity of lithium-ion batteries by up to 30 percent. An anode is the negatively charged electrode in a battery, which attracts electrons as it discharges. The company has started production of its anode, which it hopes will appeal to lithium-ion battery makers.
The company’s technology, originally developed at the University of Washington, is a process for creating carbon with desired properties. Its first products were lead-acid batteries and components for ultracapacitors, two relatively small markets compared to the one for lithium-ion batteries.
EnerG2’s new lithium-ion battery anode is made of a form of carbon in which the atoms have a disorganized, amorphous structure, compared to the crystalline structure of graphite, the material normally used for anodes. EnerG2’s “hard carbon,” as the material is called, can store 50 percent more energy per area on its surface than graphite.
A Stanford team has designed an entirely new form of cooling panel that works even when the sun is shining. Such a panel could vastly improve the daylight cooling of buildings, cars and other structures by radiating sunlight back into the chilly vacuum of space.
Homes and buildings chilled without air conditioners. Car interiors that don’t heat up in the summer sun. Tapping the frigid expanses of outer space to cool the planet. Science fiction, you say? Well, maybe not any more.
A team of researchers at Stanford has designed an entirely new form of cooling structure that cools even when the sun is shining. Such a structure could vastly improve the daylight cooling of buildings, cars and other structures by reflecting sunlight back into the chilly vacuum of space. Their paper describing the device was published March 5 in Nano Letters.
“People usually see space as a source of heat from the sun, but away from the sun outer space is really a cold, cold place,” explained Shanhui Fan, professor of electrical engineering and the paper’s senior author. “We’ve developed a new type of structure that reflects the vast majority of sunlight, while at the same time it sends heat into that coldness, which cools manmade structures even in the day time.”
The trick, from an engineering standpoint, is two-fold. First, the reflector has to reflect as much of the sunlight as possible. Poor reflectors absorb too much sunlight, heating up in the process and defeating the purpose of cooling.
The second challenge is that the structure must efficiently radiate heat back into space. Thus, the structure must emit thermal radiation very efficiently within a specific wavelength range in which the atmosphere is nearly transparent. Outside this range, Earth’s atmosphere simply reflects the light back down. Most people are familiar with this phenomenon. It’s better known as the greenhouse effect—the cause of global climate change.
Up until now, the invisibility cloaks put forward by scientists have been fairly bulky contraptions - an obvious flaw for those interested in Harry Potter-style applications.
However, researchers from the US have now developed a cloak that is just micrometres thick and can hide three-dimensional objects from microwaves in their natural environment, in all directions and from all of the observers’ positions.
Presenting their study today, 26 March, in the Institute of Physics and German Physical Society’s New Journal of Physics, the researchers, from the University of Texas at Austin, have used a new, ultrathin layer called a “metascreen”.
The metascreen cloak was made by attaching strips of 66 µm-thick copper tape to a 100 µm-thick, flexible polycarbonate film in a fishnet design. It was used to cloak an 18 cm cylindrical rod from microwaves and showed optimal functionality when the microwaves were at a frequency of 3.6 GHz and over a moderately broad bandwidth.
The researchers also predict that due to the inherent conformability of the metascreen and the robustness of the proposed cloaking technique, oddly shaped and asymmetrical objects can be cloaked with the same principles.
Using exotic particles called quantum dots as the basis for a photovoltaic cell is not a new idea, but attempts to make such devices have not yet achieved sufficiently high efficiency in converting sunlight to power. A new wrinkle added by a team of researchers at MIT — embedding the quantum dots within a forest of nanowires — promises to provide a significant boost.Scanning Electron Microscope images show an array of zinc-oxide nanowires (top) and a cross-section of a photovoltaic cell made from the nano wires, interspersed with quantum dots made of lead sulfide (dark areas). A layer of gold at the top (light band) and a layer of indium-tin-oxide at the bottom (lighter area) form the two electrodes of the solar cell. IMAGES COURTESY OF JEAN, ET AL/ADVANCED MATERIALS
Photovoltaics (PVs) based on tiny colloidal quantum dots have several potential advantages over other approaches to making solar cells: They can be manufactured in a room-temperature process, saving energy and avoiding complications associated with high-temperature processing of silicon and other PV materials. They can be made from abundant, inexpensive materials that do not require extensive purification, as silicon does. And they can be applied to a variety of inexpensive and even flexible substrate materials, such as lightweight plastics.
Would use tiny ionic currents, processing data like the human brain
Scientists at IBM claimed today that it has cracked a materials conundrum that may well create a new class of memory and logic chips.
The scientists discovered a way to operate chips using small ionic currents. That’s streams of charged atoms mimicking the way the human brain works.
Moore’s Law is close to bust at the CMOS level, IBM thinks and low power and high performance semiconductors using different techniques will soon be needed.
Architectural proposal of SinterHab moon base could be built by large NASA spider robots by using microwaves, solar energy and lunar dust
A microwave 3D-printed Moon base could be a sustainable solution for presence on the Lunar South Pole, the SinterHab concept shows. Space architects Tomas Rousek, Katarina Eriksson and Dr. Ondrej Doule have unveiled their vision for a lunar module which shows the potential of 3D printing technology from NASA. Modules would be constructed from lunar soil by microwave sintering and contour crafting making use of NASA JPL robotics system near the Shackleton crater.
Imagine that you took the solar energy and the dust from the ground and baked the dust using microwaves to directly construct any shape you wanted. On Earth it would sound like science fiction but on the Moon it would be feasible due to the unique properties of the lunar soil and the absence of anatmosphere. Microwave sintering creates a solid building material similar to ceramics, purely by microwave heating of the dust. Robots equipped with this technology could bake the lunar dust without any glue brought from Earth.
Due to the nano-sized iron particles in the lunar dust produced by space weathering, it is possible to heat the dust up to 1200 - 1500 0C and melt it even in a domestic microwave oven. When the lunar dust (regolith) is heated and the temperature is maintained below the melting point, particles bond together and the building blocks for the lunar habitat can be created. In the future, we could build structures of entire cities on the surface of the Moon by using solar energy. We can significantly decrease mass, costs and environmental impact if we don’t need to send glue or other binding agents from Earth. Furthermore, the hardening of the surrounding surface of the base would help mitigate the hazards of contamination from lunar dust, which is highly abrasive and harmful to both astronauts and equipment.
An innovative internal membrane system of SinterHab offers a module volume up to four times l than of the classic rigid modules at the same weight shipped from Earth. Nature provides inspiration for the inflatable structures in the form of foam bubbles. The intention of building several compartments with sintered walls led to a design based on the geometry of bubbles, where the forces of neighbouring bubbles are in equilibrium and enable the building of flat walls. It would be possible to make the modules large enough to accommodate even a green garden that recycles air and water for the lunar outpost. An architecturally integrated bioregenerative life support system does not only provide for the mere survival of the astronauts, but contributes to a higher level of habitability, enhancing the comfort and psychological well-being of the inhabitants.
The radiation shielding is provided by regolith structure, polymer layers of inflatable membrane and water tanks in critical places.
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EPFL scientists have developed a tiny, portable personal blood testing laboratory: a minuscule device implanted just under the skin provides an immediate analysis of substances in the body, and a radio module transmits the results to a doctor over the cellular phone network. This feat of miniaturization has many potential applications, including monitoring patients undergoing chemotherapy.
Humans are veritable chemical factories - we manufacture thousands of substances and transport them, via our blood, throughout our bodies. Some of these substances can be used as indicators of our health status. A team of EPFL scientists has developed a tiny device that can analyze the concentration of these substances in the blood. Implanted just beneath the skin, it can detect up to five proteins and organic acids simultaneously, and then transmit the results directly to a doctor’s computer. This method will allow a much more personalized level of care than traditional blood tests can provide. Health care providers will be better able to monitor patients, particularly those with chronic illness or those undergoing chemotherapy. The prototype, still in the experimental stages, has demonstrated that it can reliably detect several commonly traced substances. The research results will be published and presented March 20, 2013 in Europe’s largest electronics conference, DATE 13.
Some cubic millimeters of technology
The device was developed by a team led by EPFL scientists Giovanni de Micheli and Sandro Carrara. The implant, a real gem of concentrated technology, is only a few cubic millimeters in volume but includes five sensors, a radio transmitter and a power delivery system. Outside the body, a battery patch provides 1/10 watt of power, through the patient’s skin - thus there’s no need to operate every time the battery needs changing.
Information is routed through a series of stages, from the patient’s body to the doctor’s computer screen. The implant emits radio waves over a safe frequency. The patch collects the data and transmits them via Bluetooth to a mobile phone, which then sends them to the doctor over the cellular network.