A micromechanical biosensor with interdigitated capacitor readout

The growing demands of high-throughput, accurate and fast response biological or chemical sensors are driving the development of new detection technologies. This paper presents a micromechanical biosensor with capacitive read-out method. The proposed biosensor design consists of a fixed-fixed beam attached to an interdigitated capacitor. Implementation of the interdigitated capacitor design improves the sensitivity of the biosensor. The effects of the electrode thickness, length and the number of electrode fingers on the change of capacitance are investigated. The results show that the percentage change of capacitance is proportional to the number of the electrode fingers. Similarly, the increase in the length of the electrodes results in an increase in the percentage change of the capacitance. However, as the thickness of the electrode increases, the percentage change of the capacitance decreases.<br />