A Flexible Transparent Touch Panel Based on Ionic Liquid Channel

A flexible transparent touch panel based on conductive liquid channels is developed. The channel structures are monolithically produced in the transparent silicone resin by sacrificial etching. The height, width, and length of the flow channel are 0.017, 1.0, and 55 mm, respectively. The pitch of the channels is 10 mm. Ionic liquid as a conductive solution is introduced into the channels. The channel structures become almost invisible by filling the channel with the ionic liquid. Fabricated flexible transparent touch panels are mounted on both the flat and round surfaces, and the touch force detection is evaluated. The electrical resistances in both cases increases with increasing applied load until 6 N when a metal rod with a diameter of 5.0 mm is pushed against the surface of the touch panel.