Sound could be the key in building tomorrow’s nanostructures

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Researchers from Penn State University have found a way to precisely manipulate tiny objects using sound rather than optical instruments with a quick, energy-effective and technologically-simple technique that could have important applications in the fields of nanotechnology and biological research.

As shown with lab-on-a-chip devices, sound is proving a great way to manipulate small objects, and for a very precise reason: while light manipulation is technologically-easy to achieve, its high frequency in the electromagnetic spectrum means high energy levels are involved, which translate into a significant waste of energy for most applications. Sound waves, on the other hand, have much lower frequencies and therefore bear less energy, meaning a technique that harnesses sound rather than light will have a significantly better energy efficiency.

“Current methods for moving individual cells or tiny beads include such devices as optical tweezers, which require a lot of energy and could damage or even kill live cells,” assistant professor of engineering science and mechanics Tony Jun Huang, who was part of the research team, explained. “Acoustic tweezers are much smaller than optical tweezers and use 500,000 times less energy.”

But what makes the technique all the more interesting, particularly for possible applications in nanotechnology, is that it can be easily tweaked to position particles into well-defined patterns, providing a cheap and simple way to build nanoscale structures quickly and reliably.