In a bid to provide an alternative to high-priced, cooled IR detectors, Sarcon Microsystems Inc. of Knoxille, Tenn., has developed a microcantilever-based sensor priced at about $4000 for a 240 3 320 array. Cooled IR detectors can cost upward of $100,000. Sarcon's CEO, Don Perrine, attributes the low cost to the sensor's all-silicon makeup. The device was developed in collaboration with Sarcon's parent company, Sarnoff Corp. of Princeton, N.J., and Oak Ridge National Laboratory in Tennessee. Microcantilevers are micromachined onto the surface of a complementary metal oxide semiconductor chip and coated with a radiation absorber and a thin metal film. When exposed to IR radiation through a lens, they bend in proportion to the number of IR photons present.