Turning Information Into Energy

Japanese physicists turn Brownian motion—plus plenty of external energy—into work

3 min read
Sputtering Spinner: Scientists in Japan demonstrated the conversion of information into energy by using the Brownian motion, the random jiggles of molecules, to cause a pair of particles to rotate clockwise.

16 November 2010—Energy scavenging is all the rage these days. Sensors power themselves with harvested radio-frequency radiation, and piezoelectric roadbeds are in development to turn highway rumblings into electricity for traffic signals and streetlights. Now Japanese physicists claim to have pushed this trend to a thermodynamic extreme by harvesting the ubiquitous random vibrations known as Brownian motion. The key to doing this, they explain in this week’s issue of the journal Nature Physics, is to first gather a few bits of information.

Chuo University physicist Shoichi Toyabe and University of Tokyo physicist Masaki Sano, along with three colleagues, predict that their experimental system could produce smart devices that could power themselves using Brownian motion—the low-quality energy left over by the inexorable flow toward increasing entropy that is enshrined in the second law of thermodynamics. Experts in microelectromechanical systems, or MEMS, say it’s a worthy goal but see the Japanese experiment, at best, as a proof of principle.

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The Ultimate Transistor Timeline

The transistor’s amazing evolution from point contacts to quantum tunnels

1 min read
A chart showing the timeline of when a transistor was invented and when it was commercialized.

Even as the initial sales receipts for the first transistors to hit the market were being tallied up in 1948, the next generation of transistors had already been invented (see “The First Transistor and How it Worked.”) Since then, engineers have reinvented the transistor over and over again, raiding condensed-matter physics for anything that might offer even the possibility of turning a small signal into a larger one.

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