New Applications for Pressure Sensors

Abstract

Design and fabrication of commercial electromechanical products are usually small in size but contain complicated electronic systems. Typically, these small electronic units are packaged in metal or plastic boxes to protect from physical damage and screen out electromagnetic interference. When repairing or calibrating the selected boxes, they should be opened carefully to prevent circuitry damage, avoid unwanted circuitry operation during repairs, and to protect the safety of technical personnel. We designed circuitry with pressure sensor to address these concerns. In our experiments, mechanical components were equipped with pressure sensors and installed under a few screws which kept constant pressure applied to the sensors. Opening of the box, i.e. removing the screws, reduces the pressure applied to the sensors. That instantly changes the value of resistance R_s of the sensor. Changing R_s, in our safety circuitry disconnects power to the unit waiting to be repaired. To the contrary, in military or classified circuit applications, to prevent copying of the circuitry, changing R_s could cause destruction of the protected unit (Mil’shtein & Brooks, 2025).