Abstract: The device consists of two superimposed substrates (1 and 5) each carrying a grid of orthogonal conductive tracks (2 and so forth) facing each other from grid to grid and kept at a distance from each other by spacing rods (4). The tracks of each grid are attached to linear resistances (R.sub.AX and R.sub.AY) designed to be simultaneously connected, one to a direct-current reference potential and the other to a potential sensor, and conversely. This sensor can thus receive analog signals which are characteristic of the position of any point on the substrate (5) which is formed by a soft membrane, on which substrate a pressure is exerted which puts at least one track (6) of the grid associated with this substrate (5) into contact with one track (2) belonging to the grid associated with the other substrate (1).