Haptic Technology - Design

Design

Haptics are enabled by actuators that apply forces to the skin for touch feedback, and controllers.

The actuator provides mechanical motion in response to an electrical stimulus. Most early designs of haptic feedback use electromagnetic technologies such as vibratory motors, like a vibrating alert in a cell phone or a voice coil in a speaker, where a central mass is moved by an applied magnetic field. These electromagnetic motors typically operate at resonance and provide strong feedback, but produce a limited range of sensations. Next generation actuator technologies are beginning to emerge, offering a wider range of effects due to more rapid response times. Next generation haptic actuator technologies include electroactive polymers, piezoelectric, electrostatic and subsonic audio wave surface actuation.

The actuators require control and early haptic response systems typically vibrated the whole device. Second generation haptic control algorithms and chips have been developed that enable location specific responses to be created.

A new technique that does not require actuators is called reverse-electrovibration. A weak current is sent from a device on the user through the object they are touching to the ground. The oscillating electric field around the skin on their finger tips creates a variable sensation of friction depending on the shape, frequency, and amplitude of the signal.