A device is disclosed that includes an interface member including a
material and a manipulandum movable in a degree of freedom. The
manipulandum is able to penetrate the material. A sensor is configured to
output a position signal based on the position of the manipulandum. An
actuator is configured to output haptic feedback by applying a
compressive force to the material based on the position signal. In other
embodiments, a method is disclosed that includes receiving a position
signal associated with a position of a manipulandum, where at least a
portion of the manipulandum penetrates the interface material. Haptic
feedback is output by varying a density of the interface material based
on the position signal.