Different approaches to large tactile screens suitable for graphics

A main goal of current developments is to design very simple elements providing an inherent memory and a way of coincidence addressing. Furthermore, instead of assembling self-contained one-pin-displays, modules with more or less integrated actuators driving from 64 to up to 1024 pins will be produced. Replacing assembling by integration can reduce the costs considerably as is well known from integrated electronic circuits. Three approaches are examined and contrasted: a screen containing shape memory metal actuators, pins driven by electrorheological fluid and the polymer gel approach.