Patterned Coating of Ionic Diode Arrays Toward Flexible Moist‐Electric Generators to Power Wireless Sensor Nodes

Abstract Ubiquitous moisture is attractive for developing sustainable mobile power sources. However, how to endow moisture‐electric generators (MEGs) with fine design, mass customization, high power output, and foldability is still a largely unsolved problem. In this work, based on the Patterned Coating method, use is made of modulated carbon nanotube, nano‐Al₂O_3, and liquid metal inks to design and fabricate MEGs with properties required for their applications. A single MEG of the ionic diode type thus fabricated can generate an open‐circuit voltage (V_OC) of 1.03 V and a short‐circuit current density (J_SC) of 47.77 µA cm⁻². Through large‐area integrated fabrication, an array containing 160 MEGs can generate a V_OC of 154.1 V, and an array containing 100 MEGs can produce a short‐circuit current of 1.95 mA. In addition, the excellent wearability of MEG is verified by analyzing its electrical output performance after subjecting it to 800 cycles of bending deformations. The simple and cost‐saving fabrication technology issued from the work opens new perspectives for MEG applications and paves a path to their industrialization. For example, the customizable ionic diode arrays can meet the on‐demand power supply requirements of wireless sensor network nodes in the Internet of Things.