Soft self-powered solid-state poly(ionic liquid) piezoionic elastomer sensor for extreme temperature operation

Piezoionics is a novel electrical energy generation paradigm with great potential for self-powered soft sensors. However, the common approach of fabricating piezoionic sensors from hydrogels are plagued by challenges associated with water, such as evaporation, salt leakage, and limited sub-zero temperature operation. Here, we present a strategy using a solid-state poly(ionic liquid) (PIL) elastomer piezoionic sensor, engineered to stream only a single polarity of ions, capable of high-precision sensing even at sub-zero temperatures. The PIL, prepared by random copolymerization of ionic liquid butyl-3-methylimidazolium 3-sulfopropyl acrylate salt [BMI⁺][APS⁻] with methyl methacrylate (MA) and poly(ethylene glycol) diacrylate (PEGDA), achieves a piezoionic coefficient of 368 nV Pa⁻¹ within 0–50 kPa, a maximum voltage output of 32.2 mV at 210 kPa, and a fast response time of 20 ms. The PIL has a wide operation temperature range of −10 °C to 50 °C, which is unprecedented in any piezoionic device. Leveraging these properties, the sensor has been demonstrated in plant morphology monitoring, human physiological health monitoring, and material identification, charting a path for piezoionics to serve soft, self-powered environmental, biomedical, and robotic applications. © 2026 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.