Open menu
Nanowerk

Nanotechnology Spotlight

Behind the buzz and beyond the hype:
Our Nanowerk-exclusive feature articles

Nanotechnology Spotlight – Latest Articles

RSS Subscribe to our Nanotechnology Spotlight feed

Showing Spotlights 153 - 160 of 178 in category Electronics, NEMS (newest first):

 

Nanobionics - where the boundaries between electronics and biology become fuzzy

In case you are not old enough to remember the TV series The Six Million Dollar Man during the 1970s, the show was about an astronaut, Steve Austin, who got severely injured during a crash and became a guinea pig for bionics experiments by the CIA. In an operation that cost six million dollars, his right arm, both legs and the left eye are replaced by bionic (cybernetic) implants that vastly enhanced his strength, speed and vision. Never mind Hollywood, though, but bionics - a word formed from biology and electronics - has become a serious research field. In particular the development of artificial muscles is progressing rapidly. Nature's solution to producing fast contracting muscles is to use nanotechnology. The challenge for scientists is to mimic the intricacy of natural muscle in their artificial-muscle systems. As material scientists and engineers delve into the nanodomain, the boundaries between electronics and biology become fuzzy and this is exactly what they want: a seamless transition between the hard world of electronics and the soft world of biology.

Posted: Jul 17th, 2007

An ultralow-cost, large area way for nanoelectronics fabrication

Nanoimprinting lithography (NIL) is a simple pattern transfer process that is emerging as an alternative nanopatterning technology to traditional photolithography. NIL allows the fabrication of two-dimensional or three-dimensional structures with submicrometer resolution and the patterning and modification of functional materials. A key benefit of nanoimprint lithography is its sheer simplicity. There is no need for complex optics or high-energy radiation sources with a nanoimprint tool. There is no need for finely tailored photoresists designed for both resolution and sensitivity at a given wavelength. The simplified requirements of the technology allow low-cost, high-throughput production processes of various nanostructures with operational ease. NIL already has been applied in various fields such as biological nanodevices, nanophotonic devices, organic electronics, and the patterning of magnetic materials. Researchers at Berkeley have taken this process one step further by demonstrating that direct nanoimprinting of metal nanoparticles enables low temperature metal deposition as well as high-resolution patterning. This approach has substantial potential to take advantage of nanoimprinting for the application in ultralow cost, large area printed electronics.

Posted: Jun 27th, 2007

Transparent and flexible electronics with nanowire transistors

Thin-film transistors (TFTs) and associated circuits are of great interest for applications including displays, large-area electronics and printed electronics (e.g. radio-frequency identification tags - RFID). Well-established TFT technologies such as amorphous silicon and poly-silicon are well-suited for many current applications - almost all mobile phone color screens use them - but face challenges in extensions to flexible and transparent applications. In addition, these TFTs have modest carrier mobilities, a measure of the velocity of electrons within the material at a given electric field. The modest mobility corresponds to a modest operating speed for this class of TFTs. Organic TFTs are generally better suited for flexible applications, and can be made transparent. However, mobilities in organic TFTs are generally quite low, restricting the speed of operation and requiring relatively large device sizes. Researchers at Purdue University, Northwestern University, and the University of Southern California now have reported nanowire TFTs that have significantly higher mobilities than other TFT technologies and therefore offer the potential to operate at much higher speeds. Alternatively, they can be fabricated using much smaller device sizes, which allows higher levels of integration within a given chip area. They also provide compatibility with a variety of substrates, as well as the potential for room-temperature processing, which would allow integration of the devices with a number of other technologies (e.g. for displays).

Posted: Jun 12th, 2007

Blowing bubbles - from cling wrap to nanotechnology electronics

One of the most common methods of film manufacture is Blown Film Extrusion. The process, by which most commodity and specialized plastic films are made for the packaging industry, involves extrusion of a plastic through a circular die, followed by "bubble-like" expansion. The resulting thin tubular film can be used directly, or slit to form a flat film. Nanoscientists now have found a way to use this very common and efficient industrial technology to potentially solve the problem of fabricating large-area nanocomposite films. Currently, the problems with making thin film assemblies are either the production cost of using complex techniques like wet spinning or the unsatisfactory results of unevenly distributed and lumping nanoparticles within the film. The new bubble film technique results in well-aligned and controlled-density nanowire and carbon nanotubes (CNTs) films over large areas. These findings could finally open the door to affordable and reliable large-scale assembly of nanostructures.

Posted: May 31st, 2007

Electronics can be so transparent

One of the newly emerging areas of semiconductor technology is the field of transparent electronics. These thin-film materials hold the promise of a new class of flexible and transparent electronic components that would be more environmentally benign than current electronics. Being able to print transparent circuits on low-cost, flexible, plastic substrates opens up the possibility of a wide range of new applications, ranging from windshield displays and flexible solar cells to clear toys and artificial skins and even sensor implants. It is likely that such flexible see-through structures will find wide uses in military, biosensing and consumer goods due to the advantages of high transparency and reliable electrical characteristics. However, the emerging transparent electronics technology is facing manufacturing problems: current fabricating processes do not separate the device manufacturing from material synthesis. The transparent electronic materials, which are largely inorganic oxides. are directly deposited on the device substrate under harsh conditions which may cause damage to the existing layer or flexible substrate. The etching of small dimension oxide multilayer is also difficult due to the low selectivity of the etching recipe. New research results demonstrate that nanofabrication techniques could solve these problems.

Posted: Apr 30th, 2007

High performance electronics and sensors on flexible plastic chips

The fabrication of electronic devices on plastic substrates has attracted considerable recent attention owing to the proliferation of handheld, portable consumer electronics. Plastic substrates possess many attractive properties including biocompatibility, flexibility, light weight, shock resistance, softness and transparency. Achieving high performance electronics or sensors on plastic substrates is difficult, because plastics melt at temperatures above 120 degrees C. Central to continued advances in high-performance plastic electronics is the development of robust methods for overcoming this temperature restriction. Unfortunately, high quality semiconductors (such as silicon) require high growth temperatures, so their application to flexible plastics is prohibited. A group of researchers at the California Institute of Technology now showed that highly ordered films of silicon nanowires can be literally glued onto pieces of plastic to make flexible sensors with state-of-the-art sensitivity to a range of toxic chemicals. These nanowires are crystalline wires made out of doped silicon - the mainstay of the computer industry. By etching nanowires into a wafer of silicon, and then peeling them off and transferring them to plastic, they developed a general, parallel, and scalable strategy for achieving high performance electronics on low cost plastic substrates.

Posted: Apr 23rd, 2007

Electronic polymer nanodevices

Organic materials offer new electronic functionality not available in inorganic devices. Promising examples of novel characteristics in organic devices range from the memory effects observed in monolayers and polymer films to negative differential resistance devices. However, the integration of organic compounds within nanoscale electronic circuitry poses considerable challenges for materials physics and chemistry, and a detailed understanding of the conduction mechanisms, switching and memory is still lacking. With increasing research into very different material systems such as oxides, solid-state electrolytes, phase-change memory materials, it is becoming clear that electronic switching on the smallest length scale cannot be purely electronic phenomena. Rather, a motion of heavier constituents has to be involved that will in turn change the electronic properties. New work conducted at Bell Labs demonstrates the success of such a line of thought in molecular systems. The Bell scientists demonstrated a novel approach to creating and chemically modifying conducting electronic states in nanoscale molecular devices.

Posted: Apr 11th, 2007

Woven logic from organic electronic fibers

In the future, wearable electronics will go far beyond just very small electronic devices. Not only will such devices be embedded on textile substrates, but an electronics device or system could become the fabric itself. Electronics textiles will allow the design and production of a new generation of garments with distributed sensors and electronic functions. Such e-textiles will have the revolutionary ability to sense, act, store, emit, and move (think biomedical monitoring functions or new man-machine interfaces) while leveraging an existing low-cost textile manufacturing infrastructure. Reporting a novel approach through the construction of all-organic wire electrochemical transistor devices (WECT) , researchers in Sweden show that textile monofilaments can be coated with continuous thin films of a conducting polymer and used to create microscale WECTs on single fibers. They also demonstrate inverters and multiplexers for digital logic. This opens an avenue for three-dimensional polymer micro-electronics, where large-scale circuits can be designed and integrated directly into the three-dimensional structure of woven fibers.

Posted: Apr 4th, 2007