Transparent Switch Structure Having A Feeling of Click for Touch-Screen Interface

We developed a transparent tactile device on touch screen interface, which provides actual keystroke and feeling of click without preventing the functions of the interface. We designed and fabricated transparent switch structure using silicone elastomer with transparency of over 88%. In this case, high visibility was realized by filling the interspaces with the sealing liquid that has near reflective index as silicone. A feeling of click is yielded by buckling phenomenon of the structure and mechanical property is measured quantitatively by comparing its keystroke and reaction force on the key top. Our device structure is flat and thin, so that it can fit on the ordinal touch screen interface easily as one of the human machine interface functions.