Friday, June 24, 2011

This week in nanotechnology - June 24, 2011

For decades, researchers have been working to develop nanoparticles that deliver cancer drugs directly to tumors, minimizing the toxic side effects of chemotherapy. However, even with the best of these nanoparticles, only about 1 percent of the drug typically reaches its intended target. Researchers have now designed a new type of delivery system in which a first wave of nanoparticles homes in on the tumor, then calls in a much larger second wave that dispenses the cancer drug.

Scientists have established a biomimetic nanopore that provides a unique test and measurement platform for the way that proteins move into a cell's nucleus. This artificial nanopore is functionalized with key proteins which mimicks the natural nuclear pore and also shows the same selectivity that is found in natural pores.

The eye of the peacock mantis shrimp has led to a two-part waveplate that could improve CD, DVD, blu-ray and holographic technology, creating even higher definition and larger storage density. A team of engineers developed a method to produce periodically multilayered materials, similar to the lens in the peacock mantis shrimp, that are suitable for waveplates in the visual light spectrum and cannot delaminate because they are manufactured as one piece. This waveplate is made of two layers of nanorods that are structurally similar to those in the eye of the peacock mantis shrimp.
peacock mantis shrimp
Peacock mantis shrimp.

Turning carbon dioxide directly into graphene? Yup! Researchers report a new method that converts carbon dioxide directly into few-layer graphene (less than 10 atoms in thickness) by burning pure magnesium metal in dry ice. This synthetic process can be used to potentially produce few-layer graphene in large quantities.

Research into the use of nanotechnology in treating stroke has produced evidence of significant motor function recovery. The use of carbon nanotubes to deliver short strands of RNA – called siRNA – and induce gene silencing of specific target areas in the brain responsible for motor functions has allowed scientists to 'switch off' proteins that contribute to neuronal tissue loss. This collaborative and highly multidisciplinary project offers the possibility of a new treatment for stroke.

Improving concrete performance with nanotechnology: Every day, concrete structures crack and erode prematurely due to Alkali Silica Reactivity (ASR), a chemical reaction that causes fissures in the material as it sets. Research into the optimal use of nano-silica will create a new concrete mixture that will result in longer-lasting buildings, roadways, sidewalks, stairs, sewers, and dams.
Nanocoated 'super sand' for better purification of drinking water: Scientists have developed a way to transform ordinary sand — a mainstay filter material used to purify drinking water throughout the world — into a 'super sand' with five times the filtering capacity of regular sand by coating it with graphite oxide nanosheets.

Friday, June 17, 2011

This week in nanotechnology - June 17, 2011

A new generation of high speed, silicon-based information technology has been brought a step closer - scientists demonstrate first telecommunications wavelength quantum dot laser grown on a silicon substrate.

New engineering research at the University of Pennsylvania demonstrates that polaritons have increased coupling strength when confined to nanoscale semiconductors. This represents a promising advance in the field of photonics: smaller and faster circuits that use light rather than electricity.

A nanoscale grapevine with hydrogen grapes could someday provide your car's preferred vintage of fuel. Rice University researchers have determined that a lattice of calcium-decorated carbyne has the potential to store hydrogen at levels that easily exceed Department of Energy (DOE) goals for use as a "green" alternative fuel for vehicles.
Hydrogen adsorption on calcium-decorated carbyne chain
Hydrogen adsorption on calcium-decorated carbyne chain.

The world's first three-dimensional plasmon rulers, capable of measuring nanometer-scale spatial changes in macromolecular systems, could provide scientists with unprecedented details on such critical dynamic events in biology as the interaction of DNA with enzymes, the folding of proteins, the motion of peptides or the vibrations of cell membranes.

Team reports scalable fabrication of self-aligned graphene transistors, circuits. The research opens a rational pathway to scalable fabrication of high-speed, self-aligned graphene transistors and functional circuits and it demonstrates for the first time a graphene transistor with a practical (extrinsic) cutoff frequency beyond 50 GHz.

Friday, June 10, 2011

This week in nanotechnology - June 10, 2011

A radically new approach to the design of batteries, developed by researchers at MIT, could provide a lightweight and inexpensive alternative to existing batteries for electric vehicles and the power grid. The technology could even make "refueling" such batteries as quick and easy as pumping gas into a conventional car. The new battery relies on an innovative architecture called a semi-solid flow cell, in which solid particles are suspended in a carrier liquid and pumped through the system.

Microscopy with a quantum tip: The heart of a scanning probe microscope is a moveable, suspended tip, which, like the needle on a record player, reacts to small height variations on the surface, and turns these into signals that can be displayed on a computer. Researchers have now been able to create this tip, not out of solid material, but out of an ultra-cold, dilute gas of atoms. This "quantum tip" can be precisely positioned and enables the probing of nanostructured surfaces. With this method, more accurate measurements of the interactions between atoms and surfaces are possible and further cooling of the probe tip gives rise to a so-called Bose-Einstein condensate, which allows a significant increase in the resolution of the microscope.

IBM researchers announced the first integrated circuit fabricated from wafer-size graphene, and demonstrated a broadband frequency mixer operating at frequencies up to 10 gigahertz (10 billion cycles/second). This result opens up possibilities of achieving practical graphene technology with more high-performance, radio-frequency communication devices and is also a major milestone for the Carbon Electronics for RF Applications (CERA) program, funded by DARPA.
Optical image of a completed graphene integrated circuit
Optical image of a completed graphene integrated circuit (IC) including contact pads. The probes for testing the circuit (P1-P4) are also shown. The scale bar is 100 ┬Ám.

You can run but you can't hide - Nanotechnology is key to recovering usable fingerprints from old evidence. Researchers have made an important step towards recovering usable fingerprints from old evidence and surfaces long considered too difficult by crime scene investigators. The new method uses antibodies designed to target amino acids and can detect aged, dry and weak fingerprints that can't be captured using traditional fingerprinting methods.

Electrical engineers have long been toying with the idea of designing biological molecules that can be directly integrated into electronic circuits. University of Pennsylvania researchers have developed a way to form these structures so they can operate in open-air environments, and, more important, have developed a new microscope technique that can measure the electrical properties of these and similar devices.

Friday, June 3, 2011

This week in nanotechnology - June 3, 2011

Graphene is a two-dimensional honeycomb of carbon, just one atom thick, whose intriguing electronic properties include very high electron mobility and very low resistivity. Graphene is so sensitive to its environment, however, that these remarkable attributes can be wrecked by interference from nearby materials. Finding the best substrate on which to mount graphene is critical if graphene devices are ever to become practical. Researchers have joined forces to examine the best substrate candidates for preserving graphene's intrinsic properties.

The creation of a new quasiparticle called the "hybrid plasmon polariton" may throw open the doors to integrated photonic circuits and optical computing for the 21st century. Researchers with the Berkeley Lab have demonstrated the first true nanoscale waveguides for next generation on-chip optical communication systems.

In many ways, life is like a computer. An organism's genome is the software that tells the cellular and molecular machinery—the hardware—what to do. But instead of electronic circuitry, life relies on biochemical circuitry—complex networks of reactions and pathways that enable organisms to function. Now, researchers at Caltech have built the most complex biochemical circuit ever created from scratch, made with DNA-based devices in a test tube that are analogous to the electronic transistors on a computer chip.
A wiring diagram specifying a system of 74 DNA molecules
A wiring diagram specifying a system of 74 DNA molecules that constitute the largest synthetic circuit of its type ever made. The circuit computes the square root of a number up to 15 and rounds down to the nearest integer (the discrete square root of a four-bit integer).

A simple technique for stamping patterns invisible to the human eye onto a special class of nanomaterials provides a new, cost-effective way to produce novel devices in areas ranging from drug delivery to solar cells. The new method works with materials that are riddled with tiny voids that give them unique optical, electrical, chemical and mechanical properties. Imagine a stiff, sponge-like material filled with holes that are too small to see without a special microscope.

University of Houston researchers have developed a method for creating single-crystal arrays of graphene, an advance that opens the possibility of a replacement for silicon in high-performance computers and electronics.