Transparent touch panel with conductive liquid channel structure

We applied microelectromechanical systems technology for producing a new type of transparent touch panel with conductive liquid channels. We used a molding process for fabricating the touch panel and transparent silicone rubber material for producing the channel structures. The height, width, and length of the flow channels were 0.1, 1.0, and 40 mm, respectively, and the pitch of the channels was 10.0 mm. Two fabricated lined touch panels were stacked at a 90-deg. angle, so that the channels of both layers ran perpendicular to each other. When a finger touched and pushed the surface of the touch panel, the channel structures under the finger elastically deformed. As a result, the electrical resistance in the liquid channel increased along with the increase in the touch force. A force sensor showed excellent repeatability with a variation of 1.3%.