SPIE Photonics West 2020, San Francisco, USA
February 1 - 6, 2020 (Sun. - Thur.), Moscone Centor
Active Capacitive Sensor Circuit Using Photo-Patternable Ionic Polymer Gate Dielectric Based Solution-Processed Coplanar a-InGaZnO TFTs
Changhyeon Cho, Yongchan Kim, So Young Kim, Do Hwan Kim, and Hojin Lee
Abstract
In this paper, we propose solution-processed coplanar a-InGaZnO TFTs using photo-patternable ionic polyurethane acrylate (i-PUA) polymer as a gate dielectric. In our fabrication process, i-PUA is able to pattern micro-size (30μm) by using photocrosslinking property and maintain high capacitance through EDL. Based on developed TFTs, we fabricated an active pixel sensor (APS) circuit consisting of three coplanar a-InGaZnO TFTs for detecting capacitance changes through the difference of output voltages. Furthermore, we simultaneously fabricated a capacitive pressure sensor using an i-PUA on the same plane so as to integrated APS circuit and capacitive pressure sensor simply. Based on the experimental results, we confirmed that the proposed APS circuit could detect changes in the capacitance through various input pressure-levels in i-PUA based sensor. With these results, we believe that our proposed sensor system using the integration of APS circuit and sensor will be applicable to future wearable, human-interaction display with low-power consumption.
