Electrostatic Tactile Display without Insulating Layer

This paper explores an approach to eliminating the surface insulating layer in electrostatic (electroadhesion) tactile displays. Electrostatic tactile displays modulate the surface friction by an electrical charge between the skin and the display. Traditionally, the non-conductive dielectric layer has been considered crucial for charge accumulation, as well as for safety to prevent DC current stimulation. However, by utilizing a current control technology for electrotactile displays, we can achieve electrostatic tactile display without the insulating layer. The electrical charge is possibly accumulated in the skin itself or in the air gap between the skin and the electrodes. Safety is maintained by balancing positive and negative current pulses. Furthermore, this system is compatible with existing electrotactile displays. This paper details the system configuration, presentation algorithm, and experimental results. The preliminary trial revealed that five out of eight participants could clearly feel the vibration, confirmed by acceleration recording, while the remaining participants could not experience the sensation.