A user interface for an interactive device, the user interface comprising: an interactive surface formed by an array of displaceable surface members, the surface members having a resting position; an oscillatory signal generator configured to generate a oscillatory signal, the oscillatory signal generator being coupled to the surface members by a cable array which is configured to carry the oscillatory signal to the surface members, the surface members having a resting position with respect to the cable array; wherein the cable array is arranged such that movement of the surface members from the resting position adjusts the oscillatory signal producing a modified oscillatory signal and/or such that a modified oscillatory signal causes the surface members to move from the resting position; the user interface further comprising a signal converter which converts the modified oscillatory signal to and/or from an electrical signal of the interactive device.