BPN914: Low-Power Microheater Platform-Based Gas Sensing


Chemiresistive sensors, which transduce target gas concentrations based on the change in resistance of a sensing material, provide sensitive, low-cost detection of gaseous analytes in applications such as environmental monitoring, quality control, and clinical diagnostics. Metal oxide semiconductors (MOX) such as SnO2 are an industry-standard material system for chemiresistive sensing. MOX-based sensors typically have high baseline resistance and slow response/recovery dynamics at room temperature, and thus require on-board microheaters to promote surface reactions and desorption. Although heating greatly improves the dynamics and sensitivity of MOX-based sensors, prolonged operation at requisite temperatures (around 300 – 500 °C for most MOX) results in baseline drift as well as changes in sensitivity and selectivity. We aim to develop MOX-based sensors with stable long-term characteristics by investigating how the structural and electronic properties of MOX respond to different operating temperatures, durations, and environments. To this end, we are correlating charge transport processes elucidated by impedance spectroscopy with structural and chemical information conveyed by X-ray photoelectron spectroscopy. Mature sensors will leverage energy-efficient (~15 mW to reach 500 °C) poly-Si and SiC microheater platforms previously developed by our group to enable robust, low-power gas microsensors.

Publication date: 
August 19, 2021
Publication type: 
BSAC Project Materials (Current)
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