(a) The schematic representation of the standard TSMC 2P2M CMOS process for fabricating piezoresistive MB sensing chip dies. (b) The SEM image top view of the CMOS MEMS- based MB sensing chip. The diameter of the circular membrane structure was 600 μm and square holes in the membrane were designed for the structure releasing process. Piezoresistors were embedded in the two ends of the MB structure. (c) The schematic diagram of the specific module, including reaction tank and electrical readout for phenytoin detection with microscale volume of sample. (d) The top and side views of the entity picture of MB disposable device for phenytoin detection.