VERTICALLY-ALIGNED CARBON NANOTUBES-EMBEDDED PDMS MICROSTRUCTURES FOR FLEXIBLE TACTILE SENSOR ARRAY WITH HIGH SENSITIVITY AND DURABILITY

This paper reports a flexible tactile sensor array based on vertically aligned carbon nanotubes (CNTs)-embedded polydimethylsiloxane (PDMS) microstructures with high sensitivity and durability. The CNTs-embedded PDMS microstructures are fabricated by synthesizing vertically aligned bundles on a quadrangular pyramid-etched silicon mold and transferring them to the PDMS. This structure shows the mechanical robustness originating from axially grown CNTs. Furthermore, after transferring the CNTs from the mold, the top of the CNTs are exposed on the surface of the PDMS structure. These exposed CNTs provide an electrical connection with an electrode as well as a sensitive change in the contact area when the pressure is applied. The number of contact points between embedded CNTs also increases as the applied pressure, leading to a highly sensitive response to tactile stimulation. The tactile sensor array with microstructured CNT-PDMS composites recognizes the location and magnitude of the applied load.