Abstract: A manually deformable input device responsive to manually applied pressure. The input device comprises a deformable electroconductive material (602) configured to exhibit changes in conductance (resistance) in response to being stretched or compressed, from which an extent of manually applied pressure can be determined. An electrical interface device (604) is configured to supply electrical current through the electroconductive material (602) via a first terminal (605) and a second terminal (606), and the input device further comprises a third terminal (607) connected at a position intermediate the first and second terminals. The electrical interface device (604) is configured to receive a voltage from the third terminal (607), which is representative of a proportion of voltage drop across the electroconductive material (602). The input device operates as a potential divider sensitive to manual operation irrespective of the absolute conductance (resistance) of the electroconductive material (602).