Flexible, Transparent, Active-Matrix Tactile Sensor Interface Enabled by Solution-Processed Oxide TFTs
Yingjie Tang, Dingwei Li, Yan Wang, Fanfan Li, Yitong Chen, Kun Liang, Huihui Ren, Chunyan Song, Hong Wang, Bowen Zhu
Abstract
Flexible tactile sensors with large area and high spatial resolution are important for emerging applications in electronic skin, health monitoring, and human-machine interfaces. However, achieving flexible tactile sensor arrays with low cost, low crosstalk, high sensitivity, and high uniformity characteristics remains challenging. In this work, we demonstrate a flexible, transparent, active-matrix (AM) tactile sensor array (TSA) by monolithically integrating solution-processed indium oxide (In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> ) thin-film transistor (TFT) array with a highly pressure-sensitive micro-pyramidal film. The integrated TFT-resistive sensor (1T-1R) cell exhibits high sensitivity (29.9 kPa $^{-1})$, fast response/recovery time (21/16 ms), and robust mechanical flexibility with a bending radius of 3 mm. Furthermore, the In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> TFTs exhibit excellent uniformity by process optimization, enabling the construction of a prototypical $10 \times 10$ AM-TSA for user-interactive sensor interfaces, such as monitoring external pressure distribution and playing the Tetris game in a wearable and wireless manner.