An electrostatic micromechanical biosensor for electrical detection of label-free DNA

Abstract

An electrostatic micromechanical biosensor is demonstrated for the label-free electrical detection of DNA, based on electrostatic actuation of a double-clamped micromechanical cantilever by driving gate electrodes to establish a current path through drain and source electrodes. Intrinsic charges in DNA alter surface charges on the gate by pre-charging concept and change the pull-in voltage (V-PI), the voltage required to bring the suspended cantilever into contact with the drain electrode by induced electrostatic force. Its operation principle is verified by a numerical simulation and a capacitive model. The proposed biosensor represents a breakthrough for practical exploitation of electro-mechanical based sensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703764]