A soft acoustic sensor that someone can wear like a sticker on their skin can monitor their heartbeat and recognize spoken words, researchers say. Potential applications for the device include diagnosing medical conditions, and letting humans steer robots and play computer games without a handheld device, scientists add.
Previous sensors that could detect acoustic vibrations through the skin “were basically stethoscopes,” says study lead author Howard Yu Hao Liu, a materials scientist at the University of Illinois at Urbana-Champaign. They tended to be large and made of rigid materials, which made them difficult to wear and stifled acoustic signals.
In contrast, the new device uses miniaturized, low-power commercial MEMS accelerometers encased in sticky, elastic silicone rubber. The researchers say these accelerometers are tuned to vibration frequencies—ranging from 0.5 to 550 hertz—that are typical of sounds emitted by the body’s vital organs. Stretchable copper wires help connect these accelerometers with amplifiers, resistors, and capacitors.