Development of Capacitive Pressure Sensor for Weather Balloon Satellite: COMSOL Multiphysics

The proposed electrostatic capacitive pressure sensor is intended for measuring atmospheric pressure, on weather balloons at the -73∘ C to -33∘ C required by us. The sensor is operated in the pressure range of 1 ~Pa to 90KPa. Below the ozone layer, the sensor obtains pressure measurements up to the designated altitude. It can measure pressure using this capacitive pressure sensor, which works by monitoring changes in capacitance and diaphragm movement. The diaphragm of the sensor moves lower in response to a boundary load, shortening the distance between it and the die's grounded portion and raising capacitance. By altering the dielectric material and geometry, the sensor is optimized. The sensor is made up of a silicon die, a steel base (Steel AISI 4340), and ceramic (Nextel 480 mullite fibers), as the dielectric material. To ensure uniform application of the boundary load around the circle, the geometry of the die changed from a cuboidal shape to a cylindrical one. Based on the broad range of pressure values the diaphragm, dielectric medium, and base thicknesses have been adjusted. The diaphragm is thickened to strengthen the sensor's resistance, to greater pressures. Compared to the prior model (cuboidal die), the sensitivity has increased in our newly optimized model (cylindrical die)..