Integration of Silicon Micromechanical Arrays With Molecular Monolayers For Miniaturized Sensor Systems

The extreme sensitivity and short response times of micromechanical cantilevers used as nanoscale sensors for atomic force microscopy have recently been extended beyond those of a surface imaging tool. The use of micromechanics for sensors outperform conventional calorimeters by enabling the detection of chemical reactions involving heat changes on the femtojoule level via the well-known ``bimetallic strip'' principle. We studied surface stress changes via micromechanical transduction of self-assembling molecular systems in-situ on a receptor layer to a monolayer coverage. Those experiments can yield a detection limit of zepto (10**(-21)) molar quantities. The technique can be further extended by using a monolayer film of omega-functionalized molecules for specific molecular recognition. Our current endeavor in this exciting area is to use arrays of up to 100 cantilever sensors coated with various selective sensing elements.