SUMMARY

Numerous applications in the present day ranging from testing humidity in air to detecting miniscule quantities of potentially hazardous chemical and biological agents in the air or water supplies require the development of chemical sensors that are able to perform such functions at high sensitivity and selectively. Further it has become desirable to create lab-on-chip systems that can detect multiple chemical agents and allow for sampling and testing of environments and liquids far from conventional laboratory detections system with enhanced detection capabilities. Current challenges in this area include design and characterization of low detection limit sensors, positive identification of analytes and reducing the effect of various noise sources - both intrinsic and extrinsic to the sensor. The current work seeks to examine the performance limits of a 10-cantilever piezoresistive microcantilever array (PµCA) chemical sensor. This measurement platform will perform the aforesaid functions and allow for detection with high sensitivity and selectivity. These cantilevers measure analyte concentration in terms of the surface stress associated with analyte binding to the functionalized cantilever surface as a function of temperature. The objectives of this work are design, modeling, fabrication and characterization of this measurement platform to understand the limits of detection and sources of noise in this system. In addition, design rules for stress-based biosensors and chemical sensors for a variety of applications will be developed. The thermal characterization of the PµCA will also allow for a more complete understanding of thermal issues in chemical sensing with piezoresistive cantilever sensors and sensor arrays. A thermal sensor integrated on the piezoresistive cantilever will reduce or eliminate measurement noise associated with thermal effects. Combining these principles, cantilever-based chemical sensing with temperature control will be investigated.