Silicon Melt in Reverse!

The fact that many materials change state at a given temperature is a basic chemistry concept. However, scientists at MIT has found that silicon can exhibit a strange property of "retrograde melting" under high concentrations of certain metals dissolved in it. Basically, the compound of silicon melts at extremely low temperatures. This implies a lowered cost of manufacturing of some sillicon-based devices, new silicon nanowire structures and etc.

Reference:
Steve Hudelson, Bonna K. Newman, Sarah Bernardis, David P. Fenning, Mariana I. Bertoni, Matthew A. Marcus, Sirine C. Fakra, Barry Lai, Tonio Buonassisi. Retrograde Melting and Internal Liquid Gettering in Silicon. Advanced Materials, 2010; DOI: 10.1002/adma.200904344

Bacteria to Power Micro Machines

Scientists have discovered that common bacteria can turn into micro-gears hundreds of times larger than itself when suspended in a solution. This provides insight into bio-inspired dynamically adaptive materials for energy. The ability to harness and control the power of bacterial motions is an important requirement for further developing hybrid bio-mechanical systems driven by micro-organisms. A few hundred bacteria are working together in order to turn the gear. The speed at which the gears turn can also be controlled through the manipulation of oxygen in the suspended liquid.

Reference: Science Daily

Photonic Crystals = Incredible Insulator

Scientists have found that layering photonic crystals within the vacuum lining can prevent heat loss from invisible infrared radiation, creating an incredible insulator. Heat typically travels via methods such as convection and conduction, which both require a material medium. In addition, heat can transfer through infrared radiation, or passing through a vacuum lining to a thermos's outer wall. Photonic crystals consist of tiny nano-structures that affect how light passes through. They can be configured to block certain frequency ranges of light, including infrared radiation. Tests on the new insulator showed that heat transfer does not rely on layer thickness, but only on how fast light can travel through the material. The research team hopes that the photonic crystals is applicable in areas beyond communications and computing applications.

Reference: Science Daily

Hydrogen Storage Next Step

A team of scientists first invented the capillary array technology for use in the Soviet space program. Glass is more ideal than Steel for hydrogen storage, in terms of weight, cost and storage capacity. The hydrogen storage techhnology developed C.En has be endorsed for its safety by top German institute. (Hydrogen is highly explosive) The lightweight storage and safety factors give the technology a big commercial potential.

Reference: BusinessWeek

Paper + Nanotechnology = Greater Power

Scientists have made batteries and supercapacitors with little more than ordinary office paper and some carbon and silver nanomaterials. Lightweight printable batteries is within grasp to be molded into computers, cell phones or solar panels. At the nano-scale, paper is a tangled matrix of fibers where the surface area helps inks stick. The paper acts as a scaffold, and the carbon nanotubes act as electrodes that electrolytes in solution react with. This nanotube-paper combination offers a lightweight alternative to traditional energy storage devices that rely on metals. Calculations indicate that conductive paper coated with a kilogram of the carbon nano-tubes is more efficient than plastic-based flat energy-storage devices. Power storage is an important aspect of the power crisis.

Reference: Wired

Research Inspired by Wings

Insect wings have evolved into incredible nanoscopic material structures. Some wings are superhydrophobic, meaning they cannot become wet and the tiniest droplet of water is instantly repelled. Researchers are now using insect wings as a model for making self-cleaning. frictionless and superhydrophobic materials. If successful, development of self-cleaning, water-resistant and friction-free coatings for a range of machine components, construction materials and other applications, including nano- and micro- electromechanical systems. The team has carried out atomic force microscopy analysis of the surface of insect wings in order to determine the forces with which fine dust particles stick, or rather don't stick to the wing. The work confirms that only very small forces are needed to shed nanoscopic dust particles, two to twenty nano-Newtons.

Reference:

Micro and nanostructures found on insect wings - designs for minimising adhesion and friction. Int. J. Nanomanufacturing, 2010, 5, 112-128

30 Mile Thermometer

Researchers needs to monitor the temperature of in accessible, dangerous places on the planet without using satellite data (rough estimate). The solution is using the world's largest fiber-optic cable that records temperature at three foot intervals every ten seconds. This 30 mile detector was originally designed to monitor oil wells. It functions by firing laser pulses down the length of the optical cable and photons collide within the cable and bounces back at shifted frequencies, revealing temperatures along the entire line.

Reference: Wired

New Material Boost Data Storage

Researchers have created a new material that allow 50 times more storage in computer chips. Therefore, a finger-size computer chip will have an equivalent capacity of 20 HD DVDs. The doping process of creating the material is also useful for boosting vehicle's fuel economy and reduce heat produced by semiconductors.

Information storage is not the only specialty where advancements can be made. By introducing metallic properties into ceramics, a new generation of ceramic engines will be able to withstand much higher temperatures, allowing normal vehicles to achieve fuel economy of 80 miles per gallon. The material can also be applied to solar energy.

Reference:
Narayan et al. The synthesis and magnetic properties of a nanostructured Ni-MgO system. International Journal of Nanotechnology, 2009; 61 (6): 76 DOI: 10.1007/s11837-009-0093-8

Smallest Electronic Component: Molecular Diode

Researchers have found a way to make small, versatile diodes. The smaller size means cheaper cost and better performance for electronic devices. Diodes are important components for a broad range of applications. The idea of surpassing silicon limits with molecule-based electronic components has been around awhile. Currently, 'AC Modulation' is used by applying a little varying mechanical perturbation to the molecule.

Reference: Science Daily

'Magnetricity' Observed and Measured for the First Time

A magnetic charge can behave and interact in a way similar to electric charge in some materials, new research indicates.  It also demonstrates a perfect symmetry between electricity and magnetism - 'magnetricity'. This will lead to a reassessment of the current theories of magnetism.

In order to experimentally prove the existence of magnetic current by applying a magnetic field to a spin ice sample at a low temperature.

Reference:

S. T. Bramwell, S. R. Giblin, S. Calder, R. Aldus, D. Prabhakaran & T. Fennell. Measurement of the charge and current of magnetic monopoles in spin ice. Nature, 2009; 461 (7266): 956 DOI: 10.1038/nature08500

New Nanotechnology Technology

Chemical engineers in Oregon State University have invented a new technology to deposit "nanostructure films" on different surfaces. The technology can potentially make eye glasses cheaper and better, create solar cells that are more efficient and etc. The key to the process is use of a chemical bath, controlled by a microreactor, to place thin-film deposits on various substrates such as glass, plastic, silicon or aluminum.

Reference: Science Daily

3-D Printing with Glass

Scientist has a technique that allows a new type of glass material to create objects using a 3-D printer. Three-dimensional printers are cheap, fast way to build prototype parts. In a typical powder-based 3-D printing system, a thin layer of powder is spread over a platform and software directs an inkjet printer to deposit droplets of binder solution only where needed. The binder reacts with the powder to bind the particles together and create a 3-D object. By adjusting the ratio of powder to liquid the team found a way to build solid parts out of powdered glass, the Vitraglyphic process.

Reference: Science Daily

Superheavy Element 114 Confirmed

Scientists have been able to confirm the production of the super heavy element 114, an important aspect in nuclear science. Using the Berkeley Gas-filled Separator (BGS) at Berkeley Lab's 88-inch Cyclotron, the researchers are able to confirm the creation of two individual nuclei of element 114. Super heavy elements greater than uranium, element 92 - decay in a time shorter than the age of Earth, so these elements need to be made artificially to confirm their existence. Scientists are hoping that element 114 is stable.

Reference:
L. Stavestra, K. Gregorich, J. Dvořák, P. A. Ellison, I. Dragojević, M. A. Garcia, and H. Nitsche. Independent verification of element 114 production in the 48Ca + 242Pu reaction. Physical Review Letters, 2009; 103, 132502 DOI: 10.1103/PhysRevLett.103.132502

Compound Semiconductor Hybrid

MIT engineers figured out how to add devices made from compound semiconductors to a silicon chip that is compatible with standard chip manufacturing process. The compound semiconductor have properties that silicon alone lacks. It is faster transistors than silicon, handle more power and emit/collect light more easily.

Reference: IEEE Spectrum

Studying the Teeth

Teeth exhibit graded mechanical properties and cathedral-like geometry, and over time they develop a network of micro-cracks which help diffuse stress. The automotive and aviation industries use sophisticated materials to prevent break-up on impact such as composite materials — layers of glass or carbon fibers — held together by a brittle matrix. In teeth, fibers are not arranged in a grid, but are "wavy" in structure, which is more resilient to cracking. If engineers can incorporate tooth enamel's wavy hierarchy, micro-cracking mechanism, and capacity to heal, lighter and stronger aircraft and space vehicles can be developed.

Reference: Science Daily

Faster Printable Circuits

High-performance organic circuits is carefully made using two different materials, but researchers have used a new polymer that performs the function of both materials called ambipolar polymer. The new material and its specs are indicated in the journal Advanced Materials.

Electronics need transistors to have alternating regions that conduct negative and positive charges. They need to be aligned in order to make meaningful circuits. The cost advantage and simplicity is degraded when two necessary materials are involved in complex patterning processes. The ideal solution is to have one material that can transport electrons and holes. The new polymer consists of two alternating units, one that conducts electrons and the other conducts holes. This polymer may also work for solar cells.

Reference: http://www.technologyreview.com/computing/23298/?a=f

Control of Two-faced 'Janus' Nanoparticle

A single Janus particle less than 10 microns in diameter

(Credit: Benjamin Yellin Lab, Pratt School of Engineering)

Scientists incorporated Roman mythology when they named a unique class of minuscule particles after the god Janus, depicted as the two faces facing opposite directions.

Engineers from Duke University can control all degrees (six) of the particle's motion for the first time in history. The team used a fabrication strategy to coat the particle with smaller fraction of material which allowed the particle to be compatible with optical traps and external magnetic fields. Therefore, total control over the particles was obtained.

This opens broad range of applications and further nano-technology. It can serve as the building block for many new technologies such as the electronic paper and self-propelling mirco-machines. An online journal "Advanced Materials" covers this discovery

Reference: Science Daily

Virus Assembled Microbatteries

MIT researches report an important advance toward microscopic batteries by using a virus to assemble anodes on top of electrolyte layers. The M13 virus is made of proteins, which can be genetically modified to react with particular substances. It generates structured arrays of cobalt oxide nano-wires on top of the solid electrolyte. The creation of microscopic batteries is a difficult task in the past because the proportion of electrochemically active material inside batteries decreases along with size.

The performance of the device is the same as before. The cobalt oxide anode has a much higher charge storage capacity than the carbon-based electrodes typically used in lithium-ion batteries. It is stable throughout charging and discharging. Advantages of virus assembly include room temperature functionality and precise control over size and spacing of nano-materials.

Reference: Technology Review

Armored Polymer High-Tech Foams

Engineers at the University of Warwick have found that exposing mixtures of polymer particles and various materials to immediate freeze-drying can create an armored foam that could be used for applications like low power gas sensors at room temperature.

Background/History: Freeze-drying has been used to create foams before with rubber experiments in the 1940s. Before, to make strong and stable foam structures a straight-forward method is foaming or expanding process - introduce small discontinuities into a soft polymer then reinforce the cellular structure by polymerization or cooling.

The team at the University of Warwick make polymer foams by "ice-templating" and make building blocks from a special mixture of small particles in water. By changing parameters like nano-particle/polymer latex ratios and concentrations, it is possible to create certain pore structure. This new process allow the creation of foam based nano-composite materials that can operate at room temperature

Reference:

University of Warwick. "Icy Exposure Creates Armored Polymer High-Tech Foams."

ScienceDaily 19 August 2009. 19 August 2009 .

Regenerating Surfaces

Unlike human skin, materials such as metals do not self-heal. For example, if electroplated layer protecting the metals from corrosion is scratched, it will lose its rust protection. Scientists are working on the idea of evenly distributed fluid-filled capsules into the electroplated layer. If the layer is damaged, the fluid runs out and 'fixes' the scratch.

Currently, researches with funding from Volkswagen Foundation have developed electroplated layers with nano-capsules. The problem with this approach is that smaller capsules are more sensitive and it will be difficult to electroplate due to its aggressive chemical/reactions.

There is still a lot of work to do before what we see in movies become reality i.e. regenerating humanoid robot.

Reference: www.sciencedaily.com