A miniaturization using Surface Mount Technology of potentiometric indicator system for measuring human stress

This paper concerns miniaturization using Surface Mount Technology (SMT) of potentiometric indicator system for measuring human stress. The piezoresistive MEMS sensor is integrated with potentiometric indicator system that converts a biochemical signal into a measurable signal. The overall project involved transduction stage, filtering, voltage follower, and linearization stage. The design of this new approach is implemented using Cadence OrCAD Capture CIS 15.7 software and the miniaturization part uses SMT and troubleshooting. The advantages of SMT over the older through-hole technique are surface mount allows for much smaller components to be used which, in turn, allows for smaller, more portable and lightweight electronic device application. Details descriptions of the hardware for the circuit miniaturization will be presented. From the previous research, it has been found that for a sensor input range of 1.1 to 1.3kilo ohms, an output range of -100 to +100 millivolts is obtained. The result from the SMT testing indicates discrepancy within 10.75% was found for the last output stage on the average, which could be attributed to tolerance of electronic components and wiring. This development allowed stress measurement with relatively high precision and accuracy.