Investigation towards nanomechanical sensor array for real-time detection of complex gases

This study presents the development and characterization of a nanomechanical gas sensor array with piezoresistive detectors for a wide range of applications. The sensors, made of silicon and polymers and integrated with the piezoresistive sensors on a silicon-on-insulator wafer, convert to electrical signals the stress caused by volume change of polymer induced by gas absorption. The fabrication of the sensors incorporates a process where Polymer A (Polyolefin), Polymer B (Fluorocarbon polymer) Polymer C (Acrylic resin), and Polymer D (Amino polymer), are deposited within silicon slits, demonstrating their distinct responses to various vapor species. These sensors show swift response times and efficient recovery periods, which makes them promising for real-time multiple gas and smell monitoring applications. An array of four nanomechanical sensors with polymers shows high repeatability and sensitivity when subjected to multiple gas exposure and turn-off cycles. The gas sensor arrays, effectively monitoring fish quality over several days, suggest a potential for determining optimal storage and early spoilage detection in perishables. The study demonstrates that the nanomechanical sensor array can accurately distinguish between different gas concentrations using principal component analysis, paving the way for real-time, automated multiple gas detection and analysis without human intervention.