Chip-less wireless electronic skins by remote epitaxial freestanding compound semiconductors

Recent advances in flexible and stretchable electronics have led to a surge of electronic skin (e-skin)based health monitoring platforms. Conventional wireless e-skins rely on rigid integrated circuit chips that compromise the overall flexibility and consume considerable power. Chip-less wireless e-skins based on inductor-capacitor resonators are limited to mechanical sensors with low sensitivities. We report a chipless wireless e-skin based on surface acoustic wave sensors made of freestanding ultrathin single-crystalline piezoelectric gallium nitride membranes. Surface acoustic wave-based e-skin offers highly sensitive, low-power, and long-term sensing of strain, ultraviolet light, and ion concentrations in sweat. We demonstrate weeklong monitoring of pulse. These results present routes to inexpensive and versatile low-power, high-sensitivity platforms for wireless health monitoring devices.

Automated summary

Recent advances in flexible and stretchable electronics have led to the development of electronic skin (e-skin)based health monitoring platforms. Conventional wireless e-skins use rigid integrated circuit chips, while chip-less wireless e-skins use surface acoustic wave sensors made of piezoelectric materials, which offer highly sensitive, low-power, and long-term sensing capabilities for monitoring strain, ultraviolet light, and ion concentrations in sweat. These findings provide new routes for creating inexpensive and versatile wireless health monitoring devices.