The design and operation of an advanced bimorph microcantilever based infrared imaging detector are presented. This technology has the potential to achieve very high sensitivities due to its inherent high responsivity and low noise sensor and detection electronics. The sensor array is composed of bimaterial, thermally sensitive microcantilever structures that are the moving elements of variable plate capacitors. The heat sensing microcantilever structures are integrated with CMOS control and amplification electronics to produce a low cost imager that is compatible with standard silicon IC foundry processing and materials. The bimorph sensor structure is fabricated using low thermal expansion, high thermal isolation silicon oxide and oxynitride materials, and a high thermal expansion aluminum alloy bimetal. The microcantilever paddle is designed to move away from the substrate at elevated imaging temperatures, leading to large modeled sensor dynamic ranges (~16 bits). A temperature coefficient of capacitance, ▵C/C, (equivalent to TCR for microbolometers) above 30% has been modeled and measured for these structures, leading to modeled NEDT < 20 mK and thermal time constants in the 5-10 msec range giving a figure-of-merit  NEDT.Tau = 100-200 mK.msec. The development efforts to date have focused on the fabrication of 160x120 pixel arrays with 50 micron pitch pixels. Results from detailed thermo-electro-opto-mechanical modeling of the operation of these sensors are compared with experimental measurements from various test and integrated sensor structures and arrays.
Vanadium dioxide (VO2) thin film undergoes a semiconductor-to-metal phase transition at about 68°C, which is accompanied with abrupt changes in its optical properties. A light modulator array has been developed by surface micromachining based on this thermally induced optical switching. The good thermal isolation and the small thermal mass of the micromachined pixels prevent thermal cross talk and provide advantages of low power consumption as well as high switching speed. The VO2 pixel design was optimized by thermal and optical simulations. Active VO2 thin film was fabricated by evaporation of vanadium film followed by thermal oxidation. The light modulator array has been realized in 64 × 64 format by surface micromachining using polyimide sacrificial layer. Preliminary characterization and testing result will be presented.