Haptic

Pertaining to the sense of touch, from the Greek word haptein, to grasp. There are four types of sensory neurons (mechanoreceptors) involved in the haptic modality. The haptic, or tactile, sensory modality is the only active sense that can be used to explore our environment; vision and hearing are passive senses since they cannot act upon the environment.

• A human has approx 5 million sensors on the skin.
• Finger tips have nerve endings 1mm apart

See also: Human Machine Interface.