Microdevices for Low-Level Acetone Gas Sensing Using Tungsten Trioxides

Diabetes is one of the most prevalent diseases in the world today. It is caused by an insulin disorder that can be classified as type 1 or type 2 diabetes. Existing methods for diagnosis of diabetes are invasive which require blood sample for measuring the blood sugar level. Human breath contains low-level acetone vapour which can be used as a biomarker for early diagnosis of diabetes. Tungsten trioxide (WO3) has very high selectivity towards acetone vapour. A combination of a sensitive device with metal oxides of high selectivity can be used for low-level gas vapour detection. Piezoresistive-based microcantilevers and interdigitated electrodes (IDEs) are the most prominent gas sensor devices with high resolution. COMSOL Multiphysics software used to determine optimal design conditions to get the highest sensitivity from the microdevices. Field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), and high resolution X-ray diffraction (HRXRD) of commercial WO3 material have been acquired. Microcantilever and IDEs were fabricated using optimized dimensions for gas sensing. The WO3 sensor shows excellent sensitivity and selectivity towards acetone in the presence of different volatile organic compounds (VOCs) like ethanol, methanol, and isopropyl alcohol (IPA).