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Nanotechnology Spotlight

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

Showing Spotlights 121 - 128 of 133 in category Electronics, NEMS (newest first):

 

Giant enhancement of the carrier mobility in silicon nanowires

'Carrier mobility' is a major factor in determining the speed of electronic devices. Aggressive scaling of the complementary metal-oxide-semiconductor (CMOS) transistor technology requires a high drive current, which depends on the charge carrier mobility. As the dimensions of nanoelectronic circuits continue to shrink, it is important that the carrier mobility does not deteriorate and, if possible, improves. The search for nanostructures where the carrier mobility values can be preserved or even improved continues owing to the extremely high technological pay-off if successful. Nanowires represent a convenient system to understand the effects of low dimensionality on the carrier drift mobility. One can also look at nanowires as an ultimately scaled transistor channel. New research at the University of California - Riverside demonstrates a method for the significant enhancement of the carrier mobility in silicon nanowires. Such mobility enhancement would allow to make smaller and faster transistors and improve heat removal.

Posted: Oct 26th, 2006

Nanocomposite adhesives hold enormous potential for demanding applications in displays and electronics

Adhesives may be broadly divided in two classes: structural and pressure sensitive. To form a permanent bond, structural adhesives harden via processes such as evaporation of solvent or water (white glue), reaction with radiation (dental adhesives), chemical reaction (two part epoxy), or cooling (hot melt). In contrast, pressure sensitive adhesives (PSAs) form a bond simply by the application of light pressure to attach the adhesive to the adherend. PSAs adhere instantly and firmly to nearly any surface under the application of light pressure, without covalent bonding or activation. Waterborne pressure-sensitive adhesives solve the problem of meeting environmental regulations that forbid the emission of volatile organic compounds in manufacturing. However, often waterborne PSAs have poor adhesive performance. Another problem, particularly relevant to display technologies, is how to make an electrically-conducting material that is also flexible and optically transparent. Indium tin oxide is commonly used as a transparent electrode in displays, but it is brittle and prone to mechanical failure or scratching. Adhesives can be made electrically conductive through the addition of metal particles, but then they lose optical transparency, and their adhesiveness is diminished. New research shows that waterborne PSAs containing single-wall carbon nanotubes (SWNTs) meet the requirements of environmental regulations while improving the adhesive performance. The resulting unprecedented combination of adhesion and conductivity properties holds enormous potential for demanding applications in displays and electronics.

Posted: Oct 24th, 2006

Nanocoating woodfibers results in smart paper

Paper manufacturing is one of the mainstays of economic infrastructure and paper products influence many aspects of business and personal life. Pulping, process chemistry, paper coating, and recycling are key areas that can benefit from nanotechnology methods. One such method, layer-by-layer (LbL) assembly, is of great interest of its usage in the field of nanocoating. It allows creating nanometer-sized ultrathin films both on large surfaces and on microfibers and cores with the desired composition. Researchers at Louisiana Tech University have developed a simple and cost effective technique to fabricate an electrically conductive paper by applying layer-by-layer nanoassembly coating directly on wood microfibers during paper making process. Nanocoated wood microfibers and paper may be applied to make electronic devices, such as capacitors, inductors, and transistors fabricated on cost-effective lignocellulose pulp. The use of a conductive nanocoating on wood fibers can open the door for the future development of smart paper technology, applied as sensors, communication devices, electromagnetic shields, and paper-based displays.

Posted: Oct 18th, 2006

Flipping the spin...

Spintronics (short for "spin-based electronics") is an emergent technology which exploits the quantum propensity of electrons to spin as well as making use of their charge state. The spin itself is manifested as a detectable weak magnetic energy state characterized as "spin up" and "spin down". Spin flip length is an important parameter to know for designing spintronics devices. Because in spintronics, electron spin carries the information, it is important to know how far electrons can travel in a device before this spin information is lost. In a discovery that could contribute to the emerging field of spintronics, scientists at Oak Ridge National Laboratory (ORNL) and the Institute of Physics, Chinese Academy of Science, have demonstrated a way to measure the distance an electron travels in nanoscale materials before its spin is reversed due to scattering.

Posted: Sep 27th, 2006

Biomechanical nanoswitches open door to green bioelectronics

The ability to generate functional nanoswitches might ultimately allow the integration of nano-components into electronic components. Single molecule switches using scanning tunneling microscope (STM) manipulation have been demonstrated before. Mostly these switches are based on single atoms or small molecules and operate between two distinct states. Researchers now realized the first multi-step switching process by STM manipulation on a single molecule. Instead of small organic molecules they used a large plant molecule which is environmentally friendly and abundant in nature.

Posted: Sep 18th, 2006

A novel approach to making organic thin film transistors

Organic thin film transistors (OTFTs) based on have attracted a great deal of attention as they are the critical components to fabricate low cost and large area flexible displays and sensors for future application in organic electronics technology. However, the major problem to use organic thin film transistor in logic circuits is the high operating voltage required. Researchers in India believe this problem can be solved by using organic materials with high dielectric constant as gate dielectrics.

Posted: Aug 10th, 2006

Towards molecular electronics

A potential solution to overcoming the fundamental scaling limits of silicon-based electronic circuitry is the use of a single molecular layer that self-organizes between two electrodes: so-called molecular electronics. Nature itself is highly efficient in using self-organized structures for electronic transport (photosynthesis in plants, nerve cells, etc.), and now similar self-organization of organic molecules is used to make electronic devices. Electric transport through single molecules has been studied extensively by both academic and industrial research groups. It has been demonstrated that the size of a diode, an element used in electronic circuitry, can be reduced reproducibly below 1.5 nm. Transport data, however, typically differ by many orders of magnitude and the fabrication hurdle is reliability and yield. Researchers in The Netherlands now have demonstrated a technology to manufacture reproducible molecular diodes with high yields (>95 %) with unprecedented lateral dimensions.

Posted: Aug 7th, 2006