Damping Supramolecular Elastomer for Steady Hypothermic Sensing

Abstract Flexible temperature sensors often use gels to achieve skin‐inspired softness, but the water evaporation and freezing of hydrogel and the leakage of ionogel, cause unstable signal transmission and inaccurate measurement at sub‐zero temperatures. Here steady hypothermic sensing is achieved by designing a supramolecular elastomer containing two types of segments: a liquid‐free iontronic segment to transmit electrical charges and prevent freezing and ion leakage, and a neutral segment with pendant chains to damp vibration for stable signal transmission. The supramolecular elastomer exhibits excellent tensile properties, adhesiveness, self‐healing, and ionic conductivity at sub‐zero temperatures. A wireless temperature sensing system is fabricated based on the supermolecule elastomer, realizing accurate, steady, and sensitive real‐time temperature detection. Especially, the wireless sensor exhibits a temperature coefficient of resistance (TCR) of 8.87% °C⁻¹ from −20 to −15 °C, three to five times higher than that of most flexible sensors. There is no significant difference in the temperature detected by this wireless sensor and an infrared thermal imaging camera. Such steady and sensitive hypothermic sensing represents a step toward highly accurate sensing in cold chain transportation and beyond.