Capacitive pressure microsensors are extremely precise and reliable miniaturized pressure sensing devices. There are planar type capacitors, which transduction principle allows the transformation of a pressure variation into an electrical capacity variation. This technology can be applied to all the sectors that require accurate monitoring of pressure like for example environmental monitoring, aircraft systems, industrial plants, altitude sensing, flow sensing, gas leakage, or even in biomedical field. In fact, MIST E-R, in collaboration with a manufacturer of medical devices, employed capacitive pressure microsensors in medical equipment, precisely in a catheter for gastroenterology examination, equipped with pressure measuring points distributed along the length of the device. In this way, the catherer can map the pressure in almost the entire part of trachea/esophagus and obtain detailed information related to the mechanics of respiration, otherwise not accesible.
The sensors were tested in the range 50-1500 mbar and showed excellent sensitivity, stability over time and resolution less than 0.0001. Thanks to miniaturization, this sensing technology is particularly suitable for employment in very small layouts. Extreme precision of capacitive sensors makes them advantageous for local pressure measurements, where pressure variations in neighboring points can be very small.