—Emitting Light With Nanotubes “Liquid electrolytes boost nanotube transistor's performance” Nanomaterials that emit light will someday be key components of photonic and optical devices. But first, chemists must develop transistors that can produce photons efficiently at low voltages without much hysteresis (lag in response of current to voltage changes).
by Aaron A. Rowe | August 10, 2009
Andrews found inspiration in a burgeoning technology: sensors based on field-effect transistors. Scientists had begun modifying field-effect transistors with protein receptors that could bind small biological molecules. When the receptor snares a target, the electric field around the transistor shifts, which can be read out as a change in current through the device. Unfortunately, the approach is limited in biological environments like the brain by something called the Debye length—the farthest away a molecule can be from the transistor and still be detected. The greater a solution’s ionic strength, the shorter the Debye length because ions obscure the field effects created when the molecule binds to a receptor.
by Erika Gebel Berg | September 06, 2018
—Two-Dimensional Silicon Makes Its Device Debut “Materials: Silicene monolayers could help pave the way to faster, smaller electronics” Researchers report that they’ve fabricated transistors made of a single layer of silicon atoms connected to three electrodes. These are the first functional devices to use two-dimensional silicon (Nat.
by Matt Davenport | February 05, 2015
CELIA HENRY The company that invented the first transistor more than 50 years ago has now developed what it claims is the first truly molecular-scale transistor. The critical dimension of the new transistor--which affects output current and switching speed and is known as the channel length--is the length of just one molecule, only 12 nm. MINIATURIZERS Schön (right) and coworker Zhenan Bao devised first molecular-scale transistor. COURTESY OF BELL LABS A Bell Labs team led by physicist Hendrik Schön has created field-effect transistors made with monolayers of conjugated organic molecules built on top of doped silicon, which is structured with vertical steps [Nature, 413, 713 (2001)]. One of the challenges in constructing such small transistors is making the electrical contacts. Schön and his colleagues let self-assembly do the work. The organic molecules--4,4´-biphenyldithiol, for example--self-assemble on a thin layer of gold that serves as one electrode; a second gold layer deposited on top of the organic molecules serves as the other electrode.
by CELIA HENRY | October 22, 2001
—Improved Nanowire-Cell Connections “Versatile new design allows individual cells to be oriented over nanowire transistor arrays for better recording of the cells' electrical activity” It's already possible to connect tiny transistors fabricated from nanowires or carbon nanotubes directly to cells to record the cells' electrical activity.
by Elizabeth K. Wilson | April 20, 2009
As silicon-based transistors have become smaller, they’ve also become less efficient conductors, wasting energy and emitting heat. Enter the carbon nanotube. Scientists have long considered replacing silicon-based circuit elements with nanotubes because the tiny tubes transport electrons more rapidly and require less energy.
by Lauren K. Wolf | September 27, 2013