Solar-Powered Nanomotor.

Vincenzo Balzani, J. Fraser Stoddart and colleagues at the University of Bologna in Italy and UCLA have created a tiny four-stroke engines that can run on sunlight and emits no pollutant.

The molecule, called rotaxane, forms naturally. It’s also autonomous, meaning that it will continue operating as long as energy is available.

It can work with others, or function all by itself. It can be driven at high frequency, and in mild environmental conditions it is quite durable, staying stable for at least 1,000 cycles.

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