Stretchy diodes deliver wireless communication

Abstract

Over the past decade, researchers have made many skin-like medical and environmental sensors. But adding stretchable wireless communication circuits to these sensors has been difficult. Those radio frequency (RF) circuits rely on diodes, semiconductor devices that help convert AC power to DC power, working at megahertz frequencies. Researchers have now made the first stretchable high-frequency RF diode ( Nature 2021, DOI: 10.1038/s41586-021-04053-6). It could enable conformable sensors and radio frequency identification (RFID) tags—small electronic labels used to track objects—that can wirelessly receive or send signals. Zhenan Bao , the Stanford University chemical engineer who led the new work, has made other stretchable devices, but stretchy diodes proved to be both a materials and an engineering challenge, she says. Diodes contain a semiconductor sandwiched between electrodes and current collectors. “Electrodes and semiconductors that can pass a high current and also tolerate high mechanical deformation didn’t exist, so we had to invent