Flexible and transparent touch sensor using single-wall carbon nanotube thin-films

Here we report on the fabrication and demonstration of flexible and transparent touch sensors using carbon nanotube thin film(CNTF). We fabricated two types of touch sensors. The first type was a compressively strained CNTF pressure sensor, and the second type was a 5-wire resistive CNTF touch sensor. The change in compressively strained CNTF conductivity depended on the strength of the applied vertical pressure and with 0.2 MPa applied vertical pressure, the CNTF sheet conductance increased rapidly by 10%. We applied cyclic pressures (0.2 MPa) at 15 second intervals and found that the tactile pressure dependence was reproducible for several hundred cycles. In the case of 5-wire resistive CNTF touch sensors, the touch activation pressure of is 23 Pa. And it showed good repeatability over 10⁵ times.