Realization of a micro composite based pressure sensor: Its performance study for linearity, hysteresis and sensitivity

Abstract

The relevance of pressure sensors in daily life applications has been phenomenal in diversified disciplines such as engineering, bio-medical, automobile, aerospace etc. Making right choice of pressure sensors is crucial in any of these disciplines. Of late, the pursuit of making the pressure sensors applicable to various domains has spurred a variety of innovative activities. They are being fabricated using novel materials and unconventional fabrication methodology. Also, the advent of microelectromechanical systems has provided new horizons for a variety of realizations that led to the development of efficient and robust pressure sensors. The electromechanical characteristics of the sensing materials and the fabrication methodologies employed to realize the sensor have significant influence on performance of the sensor. This paper reports the micro composite based piezoresistive gauge pressure sensor performance study which was realized by screen printing technique. Graphite-PVC resin based dispersions are screen printed on flat, circular shaped, 1.98 mm thick stainless-steel diaphragm. The transducing layers are directly printed on the deforming polymer coated diaphragm so that the coupling factor is high, resulting in an efficient transfer of strain. Pressure cyclic study and its effect on linearity, hysteresis, sensitivity, stability etc. are investigated. The sensitivity is found to be 0.357 mV/bar. The maximum hysteresis and non-linearity are found to be less than 0.8% FSO. A fairly satisfactory sensitivity, linearity, hysteresis and stability are accomplished at a low cost. By observing the performance characteristics of the realized pressure sensor it can be used in commercial, industrial, automotive, aerospace and strategic fields. Some of the applications could be in tire pressure sensing, air filling in petrol bunks, petrol/diesel/oil/water tankers, water supply pipelines, oil/gas explorations, hydraulic jacks and mines etc.