Pressure sensing using vertically aligned carbon nanotubes on a flexible substrate

Sensing technologies have been under research and development for their varied applications from microelectronics to space exploration. With the end of Moores law in sight, there is growing demand for shrinking materials and improving sensitivity and range of sensing of sensors. Carbon nanotubes (CNTs) offer an excellent combination of small size (in the order of nanometers in two dimensions and micrometers in the third dimension), varied current conductivity (from insulating to metallic), flexibility, mechanical strength and feasibility of mass production. Here we used CNTs to fabricate pressure sensors to sense static loads of pressure and studied the characteristics of different methods of building the sensors. We offer an adhesive-absorption technique of fabrication of pressure sensors that tackles the issue of endurance of the sensors to repeated operation. We demonstrate a significant change in resistance of a vertically aligned forest of nanotubes upon application of static loads. This study will enable building of better pressure sensors for several applications.