Single molecule transistors

Sep 02, 2005

A team of scientists led by ASU biophysicist Stuart Lindsay, director of the Center for Single Molecule Biophysics at the Biodesign Institute and an ASU professor of physics, recently created the first reproducible single molecule negative differential resistor (NDR).

“NDR is the basis for memories, switches and logic elements,” Lindsay says. “It has been observed in molecules before, but never in controlled conditions, never at low voltages and not in a predictable way.”

Lindsay’s team designed a molecule, called a hepta-aniline oligomer, which belongs to a group of molecules that biochemists believe is capable of being molecular switches but that has failed to exhibit those properties in conductance experiments.

The team solved the problem by developing a technique in which the molecule could be tested in an electrolyte solution, a condition that past experiments didn’t attempt because of interaction problems between the solution and the electrodes.

By using a scanning probe microscope with an insulated probe tip to make and measure single-molecule contacts, with molecules designed to bond at their ends with a surface and the probe tip, the team was able to make reliable connections with single molecules to test their behaviors.

Lindsay stresses that the main value of the work is not in having found a molecule that could be developed into a working electrical switch, but in discovering many critical design parameters that should help in designing molecular devices.

“We have a working, rational roadmap now for how to do this, and we’re already hard at work applying it to a wide variety of potentially exciting applications,” he says.

ASU researchers presented their findings at the 230th national meeting of the American Chemical Society.

Source: Arizona State University

Explore further: Google eyes nanoparticle platform as part of health rethink

add to favorites email to friend print save as pdf

Related Stories

In a role reversal, RNAs proofread themselves

Jan 29, 2015

Building a protein is a lot like a game of telephone: information is passed along from one messenger to another, creating the potential for errors every step of the way. There are separate, specialized enzymatic ...

Micropore labyrinths as crucibles of life

Jan 27, 2015

Water-filled micropores in hot rock may have acted as the nurseries in which life on Earth began. An LMU team has now shown that temperature gradients in pore systems promote the cyclical replication and ...

Recommended for you

DNA nanoswitches reveal how life's molecules connect

Jan 30, 2015

A complex interplay of molecular components governs almost all aspects of biological sciences - healthy organism development, disease progression, and drug efficacy are all dependent on the way life's molecules ...

Holes in valence bands of nanodiamonds discovered

Jan 28, 2015

Nanodiamonds are tiny crystals only a few nanometers in size. While they possess the crystalline structure of diamonds, their properties diverge considerably from those of their big brothers, because their ...

Demystifying nanocrystal solar cells

Jan 28, 2015

ETH researchers have developed a comprehensive model to explain how electrons flow inside new types of solar cells made of tiny crystals. The model allows for a better understanding of such cells and may ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.