Low-power biomimetic ionic thermoelectric device for multi-gas olfaction

The escalating demand for intelligent multi-gas sensing has driven the need for high-performance artificial olfactory systems with enhanced power efficiency. This work proposes an innovative gas sensing mechanism enabled by the giant ionic-thermoelectric effect in solid-state ionic polymer, which overcomes the low thermopower-to-thermal conductivity (S/κ) limitation of the conventional thermoelectric materials. Using wafer-scale microfabrication technology, we demonstrate the first functional ionic-thermoelectric biomimetic olfactory device that can simultaneously resolve mixed gas analytes. This monolithic platform integrates multiple sub-100 μm sensing units, each combining an ionic-thermoelectric module with a narrow-bandpass optical filter, to selectively resolve the contributions of individual gas species in mixed-gas environments. The device achieves a record responsivity of 2340 V/W, a 20-fold improvement over commercial detectors (typically <200 V/W) and limits of detection of 1.42 ppm, 0.15 ppm, and 1.16 ppb for CO₂, CH₄ and CO, respectively. This work establishes a promising route to next-generation artificial olfactory systems based on the ionic-thermoelectric effects.