Development of a 3D-formed and thin-film backlit HMI

Abstract

During three subsequent research projects in co-operation with industrial partners, thin printed touch sensors were developed and investigated. In the first project the touch sensors employing the capacitive or piezoelectric principle were screen-printed as thin-film sheets of transparent polycarbonate. In the second project, these thin-film sheets were 3D-formed through thermoforming and over-moulding process. In the third project, a thin-film light source was printed onto the backside of the transparent sensors. The backlighting was achieved using either electroluminescence or an innovative technique of micro-LEDs suspended in a printed varnish, a proprietary method developed by the company NthDegree.