Comparison of two types of tactile sensing layer in touch screen panel for force sensitive detection

Here we present two types of Touch Screen Panels (TSPs) consisted of silicone gel and glycerin as the transparent Tactile Sensing Layer (TSL) measuring touch force(z axis) and touch position(x-y axis). The principle of the TSP is based on capacitive methods in which the distance between top and bottom substrates is varied by touch or interaction force leading the capacitance change between two substrates. Silicone gel as the TSL showed the force detection resolution of about 50gf and the dynamic range of 0-500gf. For the same test, Glycerin showed the detection resolution of 10gf and the dynamic range of 200gf. These relatively excellent results are caused from the permittivity and hardness of the new two TSL materials.