Acetone and Benzene Detection using MEMS Electro-thermal Actuation

Detection of volatile organic compounds such as Acetone and Benzene in exhaled breath is important. Acetone is a potential biomarker for screening glucose levels in blood and benzene is indicative of lung cancer. Exhaling more than the permissible concentration of these biomarkers indicates a person’s health condition. Early diagnosis of the disease is important as it helps in effective medical management, cost reduction, and also decreases the mortality rate significantly. The current diagnostics methods are costly, invasive, and cause discomfort to the patient. Detection of important biomarkers from exhaled breath can provide a simple non-invasive way of diagnosis. This paper reports a thermally actuated MEMS sensor for the detection of acetone and benzene. In response to an applied load, the simulated device design (using commercially available software) gives a linear response over a wide range of concentrations from ppb to ppm with a sensitivity of 0.54 $\mu \mathrm{m}/\mathrm{P}\mathrm{a}$ and 0.025 $\mu \mathrm{m}/\mathrm{P}\mathrm{a}$ for beam supported and ring supported respectively. The parameters of the sensor such as the microheater temperature profile, top plate’s thermal resistance, heater power, response and recovery time, etc. are also described.