Assessment of thick-film fabrication methods for force (pressure) sensors

Abstract New types of force sensors have been made using thick-film technology to achieve minimal dimensions and highest sensitivity. Using the well-known expressions for longitudinal and transverse sensitvity, a theoretical study of the perpendicular sensitivity is carried out. Two new sensors are designed based on this principle. Instead of measuring the bending stress of the ceramic carrier by the attached thick-film strain gauges, the resistors themselves are exposed to the entire load. This has led to the realization of prototypes with excellent characteristics. One sensor shows a sensitivity of 1.5%/kg applied force for total dimensions 5 mm × 5 mm × 1.2 mm. Linearity remains better than 1% even after thermal cycling between 20 and 120 °C. A low cost, highly sensitive force transducer could thus be achieved.