Fully 3D Printed Biodegradable, Wireless, and Smart Bioimplants with Voxelated Semiconductor

Abstract

Abstract 2D lithography based rigid main body with lead or structurally deformable thin-film-electronics face challenges in advanced implantable devices applications for variable target organs or tissues with complex architectures and 3D tubular morphology. 3D electronic printing emerges as a promising avenue, allowing adaptable, tailored designs for individuals within 3D structural supports. This study developed 3D-printable biodegradable electronic inks capable of printing conductor, dielectric, semiconductor, and frame materials and enabling multi-material integration for essential circuit elements within the single printing system. Notably, the direct stacking of semiconductors as building blocks was possible by room temperature conductivity enhancement and energy alignment strategy. Also the ink is composed of a thermoplastic homogeneous matrix for seamless integration. Based on the study, the ability to print solely functional electronic devices while integrating all-in-one process was verified by demonstrating the in vivo operability of tube-shaped wireless stimulators and their therapeutic efficacy in nerve recovery. The devices were lead-free, customizable to the target tissue, and remotely controlled with uniform pulses. Further advancements are proposed for 3D embedding, free-surface printing, and diverse sensor applications, highlighting the potential of 3D-printing in advancing implantable electronics.