Micro tactile sensors with a suspended and oriented single walled carbon nanotube beam embeded in PDMS elastomer

A tactile sensor utilizing a patterned and suspended SWNT film as a sensing element is reported in this paper. Dense and oriented SWNT films were self-assembled using dielectrophoresis through the monitoring of the dc resistance of the film. The SWNT film was patterned by lithography and oxygen plasma etching to form a suspended SWNT beam. PDMS primer was spin-coated on the SWNT structure, and cured to realize a robust tactile sensor. In nanoindentation test, a piezoresistive sensitivity of 5%/mN and a detection limitation of 2 µN were demonstrated. This simple and low temperature fabrication technology is believed to be very promising for flexible tactile sensors and sensor arrays in applications to smart robots, implantable clinic tools, or embedded pressure sensors in microfluidic systems.