electrotactile

Electrotactile refers to stimulation of the sense of touch through electrical currents applied to the skin or nerves. In electrotactile systems, surface electrodes evoke tactile sensations by activating peripheral nerve fibers. This form of haptic feedback is studied as a method for restoring tactile perception in people with sensory deficits or for providing tactile cues in virtual environments.

Electrical stimuli recruit cutaneous afferent fibers, typically through charged pulses. Using biphasic or charge-balanced waveforms, with controlled amplitude, duration, and frequency, researchers can evoke sensations ranging from light tingling to pressure. Spatial patterns of stimulation across electrode arrays can convey information such as texture or proprioceptive cues.

Electrotactile technology is used in sensory substitution devices (for vision or balance), in neuroprosthetics for providing tactile feedback in prosthetic limbs, in research on haptic interfaces, and in tongue-based displays (electrotactile tongue stimulation) for high-resolution sensory input. In teleoperation and VR, electrotactile cues can complement visual feedback.

Electrotactile displays may be implemented with pin-based arrays, grid electrodes, or flexible conductive fabrics. Tongue displays, such as those used in some sensory substitution experiments, exploit the high nerve density of the tongue. Safety and comfort are key considerations; stimulation must be within safe charge limits to minimize skin irritation and ensure user comfort.

See also: tactile feedback, haptic interface, sensory substitution.