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http://dx.doi.org/10.6117/kmeps.2016.23.3.021

Characteristics of Flexible Transparent Capacitive Pressure Sensor Using Silver Nanowire/PEDOT:PSS Hybrid Film  

Ahn, Young Seok (Graduate School of NID Fusion Technology, Seoul National University of Science and Technology)
Kim, Wonhyo (Smart Sensor Research Center, Korea Electronics Technology Institute)
Oh, Haekwan (Smart Sensor Research Center, Korea Electronics Technology Institute)
Park, Kwangbum (Smart Sensor Research Center, Korea Electronics Technology Institute)
Kim, Kunnyun (Smart Sensor Research Center, Korea Electronics Technology Institute)
Choa, Sung-Hoon (Graduate School of NID Fusion Technology, Seoul National University of Science and Technology)
Publication Information
Journal of the Microelectronics and Packaging Society / v.23, no.3, 2016 , pp. 21-29 More about this Journal
Abstract
In this paper, we developed a flexible transparent capacitive pressure sensor which can recognize X and Y coordinates and the size of force simultaneously by sensing a change in electrical capacitance. The flexible transparent capacitive pressure sensor was composed of 3 layers which were top electrode, pressure sensing layer, and bottom electrode. Silver nanowire(Ag NW)/poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) hybrid film was used for top and bottom flexible transparent electrode. The fabricated capacitive pressure sensor had a total size of 5 inch, and was composed of 11 driving line and 19 sensing line channels. The electrical, optical properties of the Ag NW/PEDOT:PSS and capacitive pressure sensor were investigated respectively. The mechanical flexibility was also investigated by bending tests. Ag NW/PEDOT:PSS exhibited the sheet resistance of $44.1{\Omega}/square$, transmittance of 91.1%, and haze of 1.35%. Notably, the Ag NW/PEDOT:PSS hybrid electrode had a constant resistance change within a bending radius of 3 mm. The bending fatigue tests showed that the Ag NW/PEDOT:PSS could withstand 200,000 bending cycles which indicated the superior flexibility and durability of the hybrid electrode. The flexible transparent capacitive pressure sensor showed the transmittance of 84.1%, and haze of 3.56%. When the capacitive pressure sensor was pressed with the multiple 2 mm-diameter tips, it can well detect the force depending on the applied pressure. This indicated that the capacitive pressure sensor is a promising scheme for next generation flexible transparent touch screens which can provide multi-tasking capabilities through simultaneous multi-touch and multi-force sensing.
Keywords
Flexible touchscreen; Capacitive pressure sensor; Multi-touch; Multi-force;
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Times Cited By KSCI : 2  (Citation Analysis)
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