Design of a MEMS capacitive chemical sensor based on polymer swelling

This paper details the design of a MEMS sensor to detect swelling of polymer films. The sensor is a variable capacitor composed of two electrodes separated by a chemically sensitive polymer. The polymer is chosen such that it absorbs target chemicals (analytes). Upon analyte absorption, the polymer swells, which increases the distance between the two electrodes. This changes the capacitance of the device and can be electrically detected and measured. This paper presents the design of the sensor, the fabrication steps, and polymer selection criteria for the sensor