A capacitive-type touch sensor for detecting the touch position and touch load, simultaneously, is designed and manufactured using transparent electrode material. Generally, a touch sensor senses only the touch position. However, as the touch sensor proposed in this study is designed by separating the touch position and touch load sensing parts, it is possible to recognize the touch load, in addition to the touch position. The touch sensor is mainly composed of a polyethyleneterephthalate (PET) film substrate coated by an indium tin oxide (ITO), an ITO glass substrate, and a transparent elastomer. The ITO, as the transparent electrode, has an approximately 86% light transmittance and a sheet resistance of 30 Ω/square, and is patterned by photo-lithography process. A transparent elastomer, for load recognition, is sandwiched between the two transparent substrates and senses the magnitude of the touch load by detecting the change in capacitance value due to the change in the distance between the upper and lower electrodes, generated by the touch load. The fabricated touch sensor is 183 mm in width and 234 mm in length with a 10 in. touch area. It has 32 transmit lines for signal driving, 47 receive lines for signal detection, and two channels of ground lines. It can detect multi-touch with more than 10 points and sense loads up to 700 gf, simultaneously.
Bibliographical noteFunding Information:
This work was supported by an information communication and broadcasting research development project of Ministry of Science, ICT and Future Planning [Project name: Development of Speech & Gesture Recognition Multimodal UI Smart Semiconductor for Wearable Device, R-7117-16-0176 ] and the IT R&D program of Ministry of Trade, Industry and Energy Republic of Korea [Project name: Development of Natural Multi-touch/Multi-force Technology based on Cognitive User Experience, 10043388 ]
© 2017 Elsevier B.V.
- Capacitive-type touch sensor
- Touch load
- Touch position
- Transparent elastomer
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering