Piezoionic strain sensors enabled by force-voltage coupling from ionogels

• Piezoionic strain sensors are prepared. • Ionogels display high flexibility. • Force-voltage coupling induces superior sensitivity. • Sensors present high working stability. • Subtle pulse can be detected accurately. Flexible piezoionic strain sensors with high sensitivity are critical to artificial intelligence. Solid-state ion conductors are basic components in piezoionic sensors, and have great effects on the sensing properties. Here, we have put forward an ionogel composed of polyvinyl alcohol and ionic liquid, which presents high ionic conductivity and superior flexibility. The ionogel fabrication is simple and shows potential for large-scale production. The force-voltage coupling effect makes ionogels as promising candidates for sensor application. Further, piezoionic sensors based on ionogels display good sensing properties with high working stability, and have been applied for detection of subtle pulse signals.