Abstract: A tactile feedback actuator includes a first electrode and a second electrode separated by a gap, and a surface layer above the first and second electrodes. The first electrode receives a first stimulus voltage at a first frequency and the second electrode receives a second stimulus voltage at a second frequency, and the first and second electrodes superimpose the first and second stimulus voltages to generate a total voltage that has a beat frequency less than a perception threshold frequency. An object in contact with a portion of the surface layer is caused to vibrate at the beat frequency. The first electrode and the second electrode may constitute an electrode array including a plurality of column electrode segments, and a plurality of row electrode segments. An object in contact with a portion of the surface layer above one or more electrode segments is caused to vibrate at the beat frequency.

Abstract: A tactile feedback actuator includes a first electrode and a second electrode separated by a gap, and a surface layer above the first and second electrodes. The first electrode receives a first stimulus voltage at a first frequency and the second electrode receives a second stimulus voltage at a second frequency, and the first and second electrodes superimpose the first and second stimulus voltages to generate a total voltage that has a beat frequency less than a perception threshold frequency. An object in contact with a portion of the surface layer is caused to vibrate at the beat frequency. The first electrode and the second electrode may constitute an electrode array including a plurality of column electrode segments, and a plurality of row electrode segments. An object in contact with a portion of the surface layer above one or more electrode segments is caused to vibrate at the beat frequency.

Abstract: A touch-screen device includes a display; a tactile feedback actuator arranged on the display, including a first substrate, a second substrate facing the first substrate, the first substrate and the second substrate being parallel to each other in a lateral direction, and movable relative to each other in the lateral direction; and an electrode arrangement on the first substrate and the second substrate, whereby a potential difference applied across two or more electrodes in the electrode arrangement produces an electrostatic force in the lateral direction between the first substrate and the second substrate; and a controller configured to apply a time-varying potential difference across the two or more electrodes such that the resultant electrostatic force varies in the lateral direction and induces oscillatory lateral movement of the first substrate relative to the second substrate.