Abstract: CNTs exhibit a number of excellent mechanical and electronic properties as functional materials in sensors. In particular, single walled carbon nanotubes (SWNT) are known for their band gap modulation due to mechanical strain, or electronic property-changes due to interaction with surrounding molecules, but also for their ultra-low power consumption. We discuss results on individual SWNTs as functional material in field effect transistors, mechanical and chemical sensors and options for manufacturing of CNT sensors.