Mic Also Generates Energy from Motion.
Researchers at Michigan State University have developed a sheet-like device — known as a ferroelectret nanogenerator, or FENG — that acts as a loudspeaker and microphone and can generates energy from human motion, such as swiping a finger across a screen.
“It’s a device that you can roll up and put in your pocket and then get somewhere and unroll and put it on a screen or a window or any platform and use it as a both a microphone and loudspeaker,” said Nelson Sepulveda, an associate professor of electrical and computer engineering at Michigan State University, and the primary investigator of the new study published online May 16.
The device is made of very thin layers of environmentally friendly substances, including silver, polyimide and polypropylene ferroelectret. Positively and negatively charged particles are added to the layers, which are stacked in an uneven way. The unevenness creates microscopic pockets of air between the layers that are analogous to the dipoles in piezoelectric crystals, the researchers said.