Developmaent of a Wireless Force Sensor

Abstract

Although there have been lot of studies on bruxism forces and bruxism activities, no real medical device has been developed to measure the forces that arise due to bruxism activities. In this thesis, different type of sensors were investigated to develop a suitable bruxism force detector. This sensor was also interfaced to a wireless transceiver to form a wireless force sensor. The sensors that were investigated included piezoelectric sensors, piezoresistive sensors (Honeywell FSL05N2C), Thin Film Flexi-force Sensor, constantan strain gage sensor and piezoresistive strain gage sensor. The sensors were subjected to different load cycle patterns at different rates to a maximum force of up to 200 N. The sensors were tested for their repeatability, linearity, hysteresis and drift. Experimental results show that piezoresistive strain gage sensors are best suited sensors for bruxism force detection. These types of sensors are small in size; they do give consistent results and have high voltage output that is very important for the wireless transmission The piezoresistive based bruxism force detector was interfaced to a wireless module (Zigbee) to form a complete wireless force sensor that could be used to measure bruxism forces. The wireless integrated sensor module was calibrated by means of an Instron 5848 Micro-tester. Finally an actual simulated bruxism event was successfully conducted to validate the use of the sensor as a bruxism force sensor.