Wave of the future?

It may be small, even minute but Nano is in the news most days. A MIT-led team has
published its accidental discovery in the December IEEE Spectrum Magazine, about ‘Nanodynamite: Fuel-coated nanotubes could provide bursts of power to the smallest systems’. They were measuring the acceleration of a chemical reaction along a nanotube when they found that the reaction they were monitoring actually generated power.

By coating a nanotube in nitrocellulose fuel and igniting one end, the team set off a combustion wave along it and learned that a nanotube is an excellent conductor of heat from burning fuel. Even better, the combustion wave creates a strong electric current!

But it will take some research before the researchers can learn to tamethese exotic waves and, ultimately, finding out if they’re the wave of the future!

In another paper published in Nature Communications, a team of engineers at Stanford describes how it has created tiny hollow spheres of photovoltaic nanocrystalline-silicon and harnessed physics to do for light what whispering galleries do for sound. The results, say the engineers, could dramatically cut materials usage and processing cost.

The researchers first create tiny balls of silica – the same stuff glass is made of –and coat them with a layer of silicon. They then etch away the glass center using hydrofluoric acid that does not affect the silicon, leaving behind the all-important light-sensitive shell. These shells form optical whispering galleries that capture and recirculate the light.light circulates around the circumference of the shells a few times, during which energy from the light gets absorbed gradually by the silicon. The longer the shells can keep the light in the material, the better the absorption will be.

Nano promises.