Molecules Can Be Coerced to Conduct Electricity

Miniaturizing electronics is one of the main avenues of research in the industry today, and scientists are looking to develop a variety of ways for achieving it. A group of experts in the United States has taken things down to the molecular level, where they successfully forced molecules to transport current.

This was achieved by modifying their mechanical properties, say investigators at the Arizona State University (ASU). The study was conducted by specialists at the Biodesign Institute.

According to team leader Nongjian “NJ” Tao, the group was able to develop this clever way of controlling the electrical conductance of a single molecule in hopes of being later able to create ultra-small electrical devices.

Such machines could perform a variety of useful tasks, such as for example act as nanoscale robots inside the human robot, as clean-up agents in the world's oceans, or as self-assembling structures.

According to the research paper, which was published in the latest issue of the top journal Nature Nanotechnology, creating such advanced machines would be impossible without harnessing electricity.

The devices could also be used for applications in biological and chemical sensing, as well as for improving the current standard in telecommunications and computer memory, the team adds.

But creating electronics at the molecular level has a unique set of challenges, the largest of which being the fact that quantum mechanics often prevail over Newtonian physics at this level of miniaturization.

“Some molecules have unusual electromechanical properties, which are unlike silicon-based materials. A molecule can also recognize other molecules via specific interactions,” Tao explains.

In the new experiments, the ASU team used conducting gold electrodes to sandwich pentaphenylene molecules, and then examined their electrical conductance. The group was able to cause variations in this measurement by simply orienting the molecules differently between the electrodes.

The pentaphenylene's tilt angle was proven to have the most significance on the outcome of the experiments. ASU scientists plan to continue this work, until they are able to create circuits that use the newly-found data in practical applications.

Funding for the investigation was secured through the Basic Energy Science program operated by the US Department of Energy (DOE).

Tao holds joint appointments at ASU, as a professor in the Ira A. Fulton Schools of Engineering School of Electrical, Computer, and Energy Engineering, and as an affiliated professor of chemistry and biochemistry, physics and material engineering.