Patent ID: 7556775

Claim:
A microelectronics based chemical sensor comprising: a first active beam having at least one end attached to a structure and a chemically selective material layer disposed on the first active beam; excitation means for causing the first active beam to deflect; a first resistor disposed on the first active beam, the first resistor having a resistance that changes responsive to a deflection of the first active beam; and two reference cantilevered beams disposed on each side of the first active beam, each of the reference cantilevered beams having a resistor disposed thereon, wherein the first active beam and the reference cantilevered beams are arranged within a same aperture of the structure and extend in a same direction within the aperture, the first resistor on the first active beam and the resistors on the reference cantilevered beams being elements of a Wheatstone bridge, wherein an output of the Wheatstone bridge corresponds to an amount of a chemical sorbed by the material layer.