Single-side micromachined low-cost quad-cantilever sensors with a high-sensitive monolayer self-assembled for trace TNT detection

A SiO 2 quad-cantilever micro-sensor with a self-sensing piezoresistor integrated is developed for on-the-spot chemical detection. Four piezoresistors are integrated in four cantilevers and the sensing signal is outputted from a half-sensitive Wheatstone bridge. The new single-sided micromachining process features low-cost and high-yield. Modified with a novel self-assembled monolayer (SAM) on two sensing cantilevers, detection for the vapor of trinitrotoluene (TNT) achieves a resolution about tens of ppt.