Editing Haptic technology (section)

== Types of mechanical touch sensing ==
Human sensing of mechanical loading in the skin is managed by [[Mechanoreceptor]]s. There are a number of types of mechanoreceptors but those present in the finger pad are typically placed into two categories. Fast acting (FA) and slow acting (SA). SA mechanoreceptors are sensitive to relatively large stresses and at low frequencies while FA mechanoreceptors are sensitive to smaller stresses at higher frequencies. The result of this is that generally SA sensors can detect textures with amplitudes greater than 200 micrometers and FA sensors can detect textures with amplitudes less than 200 micrometers down to about 1 micrometer, though some research suggests that FA can only detect textures smaller than the fingerprint wavelength.<ref>Fagiani, R., & Barbieri, M. (2016). A contact mechanics interpretation of the duplex theory of tactile texture perception. Tribology International, 101, 49–58.</ref> FA mechanoreceptors achieve this high resolution of sensing by sensing vibrations produced by friction and an interaction of the fingerprint texture moving over fine surface texture.<ref>Scheibert, J., Leurent, S., Prevost, A., & Debrégeas, G. (2009). The role of fingerprints in the coding of tactile information probed with a biomimetic sensor. Science, 323(5920), 1503-1506.</ref>