A progressive SAW tactile display on a PC mouse button

We have developed a tactile display using surface acoustic wave (SAW). A pulse modulated driving voltages excite temporal distribution of shear force in a pad on the surface of SAW substrate. There are two transducers on the surface to excite alternative shear force. The force can be perceived as tactile sensation at mechanoreceptors in the finger skin. To enhance the force, force transformer was improved. The display was installed on a computer mouse button. Reproduction of human tactile sensation, such as the roughness sensation of rubbing a solid surface, was demonstrated using the computer screen and the mouse. The mouse could display tactile sensation successfully. Difference of roughness was tested by another experimental equipment.