Chemical sensor based on quartz microresonators

A novel chemical sensor is proposed that consists of an array of quartz microresonators. It is shown that a microresonator can act as a quartz crystal microbalance and as a calorimeter, simultaneously, because quartz resonators can be highly sensitive to both mass and temperature changes. By applying a variety of thin-film adsorbers to the different resonators in an array and observing the pattern of frequency changes due to an unknown that is admitted into the resonator array enclosure, one can detect and identify chemical and biological agents. The total frequency change of an individual resonator will be the sum of the frequency change due to mass loading and the frequency change due to the change in temperature resulting from the heats of adsorptions or reactions. It is shown that the proposed sensor is capable of detecting on the order of 10/sup -6/ monolayer of a material deposited onto the resonators' surfaces.