A Detector Based On The Microcantilever Piezoresistance Sensor

With the development of the technology, the microcantilever piezoresistance sensor hasbeen used more widely. Because of the microcantilever sensor’s output is usually very weak,and there are lots of noises in it, it is necessary to design a detector to pick up the weak signalunder the strong interference of the noise.Through the analysis of the requirement of the sensor detector, the paperpresents the design of the detector. A high-precision bridge zero circuit has been designedafter the Wheatstone bridge circuit has been improved according to its existing shortcoming.Use the lock in amplifier, the weak signal can be effectively extracted from the backgroundof strong noise. The paper use MSP430F149 to control the amplifier module, lock in amplifiermodule, LCD module. Through the serial communication module to communicate with theupper computer. The upper computer collects the voltage signal output by the sensor usingVB software, then displaying it in waveform. It can restart zero setting and adjust theamplification of the system by the way of sending command via serial port. This system hasadvantages like simple hardware circuit, low power consumption and friendly interface, etc.