Figure 1.

Concept of digital electrochemistry and its application in heterogeneous material integration. a) Schematic illustration of the a‐IGZO TFT active‐matrix for addressing the electrochemical reactions. b) Schematic illustration of the digital electrochemical reaction cell, where the a‐IGZO TFT active‐matrix is used as the working electrode (WE), and the counter electrode (CE) is grounded. c) Site‐selective electrochemical reactions are carried out for in situ functional material deposition and heterogeneous integration. Depending on the functionalities of the locally deposited electroactive materials, I) active‐matrix‐driven electrochromic patterns and II) active‐matrix‐driven PPy actuators are fabricated.