Two different position sensitive devices for large-area detection of light points and objects are presented. The core of the
system consists of a luminescent foil, where impinging laser light is absorbed and the fluorescence light is coupled out
via attached silicon photodiodes. Due to a direct relation between the signal amplitude and the distance to the
photodiodes, this detector can be used for pinpointing laser spots over large areas. When fixing small stripes of the
detector inside a rectangular frame, the foil can be used for object tracing over large-areas as well.
Thin polymer foams with a closed cell void-structure can be internally charged by silent or partial discharges
within the voids. The resulting material, which carries positive and negative charges on the internal void surfaces
is called a ferroelectret. Ferroelectrets behave like typical ferroelectrics, hence they provide a novel class of ferroic
materials. The soft foams are strongly piezoelectric in the 3-direction, but show negligible piezoelectric response
in the transverse direction. This, together with a very low pyroelectric coefficient, make ferroelectrets highly
suitable for flexible electroactive transducer element which can be integrated in thin bendable organic electronic
devices. Here we describe some fundamental characteristics of cellular ferroelectrets and present a number of
promising examples for a possible combination with various functional polymer systems. Our examples focus on
flexible ferroelectret field-effect transistor systems for large-area sensor skins and microphones, flexible large-array
position detectors (touchpad), and stretchable large-array pressure sensors.