Vibrotactile

Vibrotactile refers to haptic feedback produced by mechanical vibrations transmitted to the skin. It relies on the sense of touch to convey information through patterns of vibration rather than through large movements of limbs. In devices, vibrations are generated by actuators controlled by signals corresponding to the information to be conveyed.

Common vibrotactile actuators include eccentric rotating mass motors, linear resonant actuators, and piezoelectric actuators. By varying frequency, amplitude, and pulse timing, designers encode data as patterns that users perceive as distinct sensations. The typical useful frequency range for human skin spans roughly from 20 to 400 Hz, and different receptors in the skin respond to different portions of this range, with higher-frequency stimuli often perceived as sharper or buzzier.

Applications of vibrotactile feedback are widespread. In consumer electronics, it signals alerts, confirmations, and navigation cues on smartphones, wearables, gaming controllers, and automotive interfaces. Vibrotactile arrays can create spatial patterns to indicate direction or location. In assistive technology, tactile displays and Braille-like skins convey information to users who are visually impaired. In research and entertainment, vibrotactile cues are used in virtual reality, rehabilitation, and prosthetics to augment perception and interaction.

Design considerations center on maximizing information content while preserving comfort and battery life. Perception varies with stimulation site, contact force, and sensory adaptation, so short, discrete pulses are common. Multimodal feedback and careful timing help prevent sensory overload and improve usability.