Highly sensitive capacitive tactile sensor based on silver nanowire using parylene-C stencil patterning method

In this paper, we develop a sensitive capacitive tactile sensor based on silver nanowire with 15 by 15 multichannel array structure using the parylene-C stencil patterning method. The parylene-C stencil method could define structures with line width less than 30 μm using only conventional MEMS fabrication processes. Also the sensor structure including the air gap with line width of 500 μm and height of 40 μm could be fabricated simply using multi-stacked spin-coated polydimethylsiloxane structure by oxygen plasma bonding method. The sensitivity of this tactile sensor was measured to be 3.8 MPa−1 until 50 kPa using a measurement setup including the force gauge and the impedance analyzer. Also various stamp shapes could be detected with 1 mm by 1 mm lateral resolution while the pressure of 100 kPa was applied.