Ultrathin Serpentine Insulation Layer Architecture for Ultralow Power Gas Sensor

Abstract

Toxic gases have surreptitiously influenced the health and environment of contemporary society with their odorless/colorless characteristics. As a result, a pressing need for reliable and portable gas‐sensing devices has continuously increased. However, with their negligence to efficiently microstructure their bulky supportive layer on which the sensing and heating materials are located, previous semiconductor metal‐oxide gas sensors have been unable to fully enhance their power efficiency, a critical factor in power‐stringent portable devices. Herein, an ultrathin insulation layer with a unique serpentine architecture is proposed for the development of a power‐efficient gas sensor, consuming only 2.3 mW with an operating temperature of 300 °C (≈6% of the leading commercial product). Utilizing a mechanically robust serpentine design, this work presents a fully suspended standalone device with a supportive layer thickness of only ≈50 nm. The developed gas sensor shows excellent mechanical durability, operating over 10 000 on/off cycles and ≈2 years of life expectancy under continuous operation. The gas sensor detected carbon monoxide concentrations from 30 to 1 ppm with an average response time of ≈15 s and distinguishable sensitivity to 1 ppm (ΔR/R0 = 5%). The mass‐producible fabrication and heating efficiency presented here provide an exemplary platform for diverse power‐efficient‐related devices.