Rapid Prototyping of Ultralow‐Cost, Inkjet‐Printed Carbon Microelectrodes for Flexible Bioelectronic Devices

Abstract

Gaining better understanding of the human brain using chip‐based devices and promoting the recovery of lost biological functionality through implants are long pursued endeavors driven by advances in material science, bioelectronics, and the advancing silicon technology. While conventional bioelectronic and neuroelectronic devices typically rely on cleanroom‐based processing, a rapid prototyping technique is proposed that is based on high‐resolution inkjet printing featuring nanoporous carbon electrodes that yield excellent cell–chip coupling. This study aims to overcome two major limitations of conventional approaches that make the development of neuroelectronic devices very challenging and limit a wider use within the research community as well as industry: high costs and lack of rapid prototyping capabilities. These challenges are addressed with an all‐printed, high‐resolution approach that makes use of flexible polymer substrates and is fabricated on a fully digital printing platform. The manufacturing of a chip consumes less than 60 min and costs a few cents per chip. This study introduces nanoporous carbon as a cell‐interfacing electrode material that features outstanding properties for extracellular recording of action potentials and stimulation indicating that the printed carbon chips have the means to be used as a versatile neuroelectronic tool for in vitro and in vivo studies.

Optimization of makerspace microfabrication techniques and materials for the realization of planar, 3D printed microelectrode arrays in under four days

“…25 This resolution can be competitive with other makerspace fabrication methods such as inkjet printed MEA. 19,26 With 3D PICLmM, a 3D printed MEA with an electrode density of 3 Â 3 was previously demonstrated as a proof of concept. 22 Optimizing the design, process and materials of this 3D PICLmM approach would allow for a desired end product of a transparent, high density, single well MEA that could be "used and tossed" during research.…”

Additive Manufacturable Materials for Electrochemical Biosensor Electrodes

“…These AM technologies are capable of one-step printing both the conductive and biorecognition layers, and hence will facilitate the electrode fabrication process. For electrode preparation that necessitates annealing, future work should find a solution to accelerate the postprocessing stage (e.g., annealing) in order to realize the goal of on-demand printing, such as flash annealing that can anneal in the order of milliseconds, [284,285] and subsequently elucidate the effects of flash annealing on the final electrochemical performance.…”

Ultrasoft Silicone Gel as a Biomimetic Passivation Layer in Inkjet‐Printed 3D MEA Devices

“…The primary advantage of this technology over that of the conventional clean-room technology is the ability to perform rapid prototyping and to fabricate micropatterns directly onto various substrates, including PEN, PDMS, and hydrogels. [9,21,23,24] Herein, we further took the advantage of inkjet printing that 3D microstructures can be feasibly fabricated by jetting multiple droplets at identical sites. Although the lateral resolution of the microstructures fabricated with inkjet printing is generally restricted to >20…”