The lack of tactile sensation in current upper limb prostheses is the key limitation to enable more intuitive use of the prosthesis and restore the functionality of the natural limb. Electronic skin in the form of tactile sensing arrays can be integrated onto the upper limb prosthetic device to record information about touch, given back to the amputee as a sensory feedback. This contribution focusses on the development of tactile sensing arrays based on PVDF-TrFE piezoelectric polymers. Both piezoelectric polymer sensors and metal contacts have been screen-printed on a transparent plastic foil. The geometric layout and size of the 4×4 array is suitable for prosthesis fingertips. Preliminary experimental validation of the skin patches is reported in this paper.

Ferroelectric material supports both pyro- and piezoelectric effects that can be used for sensing pressures on large, bended surfaces. We present PyzoFlex, a pressure-sensing input device that is based on a ferroelectric material. It is constructed with a sandwich structure of four layers that can be printed easily on any material. We use this material in combination with a high-resolution Anoto-sensing foil to support both hand and pen input tracking. The foil is bendable, energy-efficient, and it can be produced in a printing process. Even a hovering mode is feasible due to its pyroelectric effect. In this paper, we introduce this novel input technology and discuss its benefits and limitations.