Three-dimensional triboelectric nanogenerator manufacturing using water transfer printing

Triboelectric nanogenerators (TENGs) have been widely studied due to their efficient energy harvesting capabilities and fast electrical response signals. In this study, a processing method based on water transfer printing (WTP) is developed for preparing TENG devices with three-dimensional (3D) structures. With this method, electrodes and ink layers can be integrated onto a variety of 3D objects to form a one-piece structure, which offers advantages including application to 3D surfaces, abrasion resistance, handling ease, adaptability, and decorativeness. The process is taken to prepare a 5 × 5 cm2 single-electrode TENG (IF-TENG), with FEP serving as the negative triboelectric layer and ink serving as the positive triboelectric layer. The TENG's open-circuit voltage and short-circuit current are 184 V and 1.53 μA, respectively. Additionally, a door handle TENG (DH-TENG) device has been built for practical application demonstrations. The DH-TENG device is used in wireless alarm systems that prevent children from accidentally ingesting medication. It is also used in self-powered guidance systems that illuminate LED arrow lights to help the elderly or children at night. Seamless integration of 3D surface TENG devices using WTP is expected to have applications in smart home systems, smart transportation and security, wearable electronics, and energy harvesting.