3D‐Printed Hygroscopic Polymer Networks for High‐Humidity Triboelectric Nanogenerators to Wirelessly Power Implantable Electronic Devices‐ A Conceptual Pathway

ABSTRACT High humidity typically degrades triboelectric nanogenerator (TENG) performance by dissipating surface charge. We present a printable strategy that leverages ambient moisture to enhance output by integrating polar hydrophilic networks via liquid crystal display (LCD) 3D printing. Photocopolymerization of acrylic acid (AA), 2‐hydroxyethyl acrylate (HEA), and N‐hydroxyethyl acrylamide (HEAA) with PEGDA yields micrometre‐thin films rich in ─COOH, ─OH, and ─CONH─ groups. These groups immobilize water molecules through hydrogen bonding, forming a stable interfacial‐polarization tribolayer that resists charge loss. Optimizing the HEAA:PEGDA formulation and incorporating 5 wt.% sulfobetaine methacrylate (SBMA) creates a trimer network with enhanced dipole density, achieving outputs of 45.6 µA, 802 V, and a peak power density of 48.4 W m − 2 at 90% relative humidity. Density functional theory (DFT) and molecular dynamics (MD) simulations reveal water‐enhanced dipole moments and robust bound‐water interactions that strengthen polarization. The photocurable resin enables printing of complex micro‐architectures and flexible wearables, demonstrated in a Morse‐code finger‐sleeve TENG and an insole sensor distinguishing gait patterns. A proof‐of‐concept TENG‐powered backscatter communication system showcases wireless energy transmission, addressing battery replacement challenges in implantable devices.