A nanosensor technology has been developed using single walled carbon nanotubes (SWNTs) on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. These sensors have been exposed to nitrogen dioxide, methane, acetone, benzene, nitrotoluene, ammonia, and chlorine in the concentration range of ppm to ppb at room temperature. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, carbon nanotube based chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for space and defense applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for space and home security applications.
Purdue University, West Lafayette, IN