Selective Stimulation Method for Tactile Synthesis

In human skin, tactile receptors generate elementary sensations such as touch, pressure, vibratory sensation, pain, temperature sense, and so on. A tactile impression is an integrated sensation of these elementary sensations. To present tactile feel arbitrarily, stimuli applied to these receptors should be controlled selectively and quantitatively. As mentioned previously, tactile receptors cannot sense the physical factors of environments directiy. They detect only the skin deformation caused by contacting objects. A tactile illusion can be provided by the reproduction of the activities of tactile receptors, regardless of the inner deformations. 

For the IPMC tactile display, selective stimulation is realized by changing drive frequencies, using the receptors response characteristics. It was confirmed by a subject s introspection that the contents of sensation vary with the change of drive frequency as follows  

10-100 Hz periodic pressing or fluttering sensation, as if the surface of a finger is wiped with some rough material (FA I). 

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