New sensor achieves record-level alcohol sensitivity at ultra-low power

Researchers from Yonsei University and collaborators have developed a novel low-power gas sensor that achieves ultra-sensitive detection of ethanol at parts-per-billion levels. The sensor integrates ultrathin ruthenium dioxide nanosheets with a tin dioxide thin film, creating a hybrid structure that significantly enhances ethanol detection. The ruthenium dioxide nanosheets provide a high surface area and strong catalytic activity, accelerating ethanol molecule reactions on the sensor surface. Additionally, interactions between the nanosheets and tin dioxide amplify the electron depletion layer, increasing changes in electrical resistance and making the sensor over three times more responsive than conventional devices. Built on a suspended membrane with a microheater, the sensor operates continuously using less than 30 milliwatts of power, detecting ethanol concentrations from 10 parts per million down to about 5 parts per billion. It demonstrated stable performance over nearly a month, resisted interference from common gases, and reliably tracked real-time breath alcohol levels consistent with commercial breathalyzers. The design’s compatibility with existing microfabrication techniques