Highly sensitive acetone gas detection using an optical interferometric surface stress sensor

We investigated the acetone gas sensitivity of an optical interferometric surface stress sensor composed of an ultrathin freestanding Parylene-C membrane and a PMMA gas-absorbing layer. The sensor structure consists of a 1 mm diameter cavity with a 40 nm thick Parylene-C membrane and a 208 nm thick PMMA layer. Membrane deformation was measured in response to varying acetone gas concentrations to evaluate the sensor’s responsiveness. The results showed a gradual increase in deformation with increasing acetone concentration, with a sharp rise observed above 151 ppm. Notably, the membrane deformed by 120 nm at 302 ppm and up to 400 nm at 1512 ppm, demonstrating high sensitivity to acetone gas. This study suggests that the sensor, originally designed for ethanol detection, can be effectively extended to detect acetone, indicating its potential applicability to a broader range of volatile organic compounds (VOCs).