A muscle that plays music?

By Casey Frye, CCNN Writer

muscle music
The transparent circular muscle plays music from YouTube!

Our neurons use tiny electric charges to communicate with each other and move our bodies, similar to the volts electronics use. There is a huge difference, however, between our bodies and gadgets – we are squishy and durable, whereas they are often hard and fragile! Scientists have tried again and again to make electronic devices that can stretch and conduct electricity as well as our bodies, but the task has never been an easy one. That is, until chemists from Harvard University created a very special artificial muscle!

“The whole project started with this mismatch in mechanics between living organisms, which are soft, and our electronics world, which is hard and stiff,” said Christoph Keplinger, a Harvard researcher who worked on the project in the Department of Chemistry and Chemical Biology.

To make the muscle, the team of chemists created a hydrogel – a watery gel – and polymers – a chain of identical molecules – that could conduct electricity. They then sandwiched the gel and polymers around a thin rubber sheet to form a clear material that can stretch up to five times it’s size, yet still conduct electricity!  When the Harvard scientists ran an electric current through the artificial muscle, it tensed just like the muscles in our bodies. Depending on how weak or strong the charge was, they could control how much the artificial muscle flexed or relaxed.

“[The] team combined, in a very clever way, two known things,” said John Rogers, a materials science professor at the University of Illinois, who has worked on flexible devices in the past. “The result – a transparent, artificial muscle – is something that is new, and potentially important as a technology…” The clear material would be perfect to use as a stretchy touch screen or a flexible medical implant. In fact, since it is very similar to the tissue in our body, the artificial muscle can potentially lead to lifelike robots!

The coolest part for me though, is that the material can also work as an audio speaker. When researchers equipped their creation with wires, plugged it into an iPod, and hit play, the artificial muscle began to fill the room with music! I could definitely use it to blast my favorite playlist!

Images and video courtesy of School of Engineering and Applied Sciences at Harvard.