3D Printing of Robust High‐Performance Conducting Polymer Hydrogel‐Based Electrical Bioadhesive Interface for Soft Bioelectronics

Abstract

Electrical bioadhesive interface (EBI), especially conducting polymer hydrogel (CPH)‐based EBI, exhibits promising potential applications in various fields, including biomedical devices, neural interfaces, and wearable devices. However, current fabrication techniques of CPH‐based EBI mostly focus on conventional methods such as direct casting, injection, and molding, which remains a lingering challenge for further pushing them toward customized practical bioelectronic applications and commercialization. Herein, 3D printable high‐performance CPH‐based EBI precursor inks are developed through composite engineering of PEDOT:PSS and adhesive ionic macromolecular dopants within tough hydrogel matrices (PVA). Such inks allow the facile fabrication of high‐resolution and programmable patterned EBI through 3D printing. Upon successive freeze‐thawing, the as‐printed PEDOT:PSS‐based EBI simultaneously exhibits high conductivity of 1.2 S m⁻¹, low interfacial impedance of 20 Ω, high stretchability of 349%, superior toughness of 109 kJ m⁻³, and satisfactory adhesion to various materials. Enabled by these advantageous properties and excellent printability, the facile and continuous manufacturing of EBI‐based skin electrodes is further demonstrated via 3D printing, and the fabricated electrodes display excellent ECG and EMG signal recording capability superior to commercial products. This work may provide a new avenue for rational design and fabrication of next‐generation EBI for soft bioelectronics, further advancing seamless human‐machine integration.