Flexible Active-Matrix Tactile Sensor Arrays with High Density of 4096 pixels/cm2and In-Array Sensitivity of 51 kPa-1

Flexible tactile sensor arrays are crucial to enable robotics with human-like tactile perception. However, there is a trade-off between high density and sensitivity in sensor arrays, because signal crosstalk among adjacent pixels gradually becomes serious with increased pixel density. In this work, we demonstrate a flexible active-matrix (AM) tactile sensor array (TSA) with both high pixel density and sensitivity, by monolithically integrating a 64 x 64 lanthanum-doped indium zinc oxide (Ln-IZO) thin-film transistor (TFT) array (4096 pixels, 1 x 1 cm2) with a hierarchically micro-/nanostructured high pressure-sensitive film. The flexible AM-TSA exhibits a high spatial resolution of 150 um, high in-array tactile sensitivity of 51 kPa^-1, fast response/recovery time (51/32 ms), a low detection limit of 2.5 Pa, and robust mechanical stability, feasible for applications in tactile robotics.