Aerosol Jet Printing of 3D Biocompatible Gold Nanoparticle-Based Micro-Structures

Aerosol Jet® Printing (AJ®P) is an additive manufacturing (AM) technique for the deposition of a functionalized jet on free-form substrates. AJ®P is mainly exploited for 2D printed electronics, nevertheless, is gaining attention in the bioelectronic field. Few emerging studies have also established AJ®P as a micro-AM 3D printing technique. In this context, the 3D AJ®P process has not been deeply analysed yet. This work proposes an unique study of novel 3D AJ® printed gold microstructures, as arrays of micropillars ≥40 µm, with aspect ratios ARs ≤9 and print times ≤10 min. Print parameters were investigated via a full factorial design against shape fidelity and resolution, using a layer-by-layer strategy. Specimens were thermally sintered, without any binding. Optical, electrical, and biocompatibility tests were conducted and a flexible 3D microelectrode array was printed as proof-of-concept. Future applications include in-vitro bioelectronics, thermoelectric, and batteries.