Fabrication and Characterization of 3D Microelectrode Arrays (3D MEAs) with "Edge-Wrapped" Metal Interconnects and 3D-Printed Assembly Rigs for Simultaneous Optical and Electrical Probing of Nerve-on-a-Chip^® Constructs

We have developed a novel microfabrication and assembly strategy for the realization of 3D Microelectrode Arrays (3D MEAs) which allows for simultaneous optical and electrical probing of a Nerve-on-a-Chip ^® construct. Specific microfabrication and assembly process innovations include "edge-wrapped" metal interconnects and custom Digital Light Processing (DLP) 3D printed transition rigs respectively. A Nerve-on-a-Chip ^® construct consisting of primary rat Dorsal Root Ganglion (DRG) cells are further seeded and grown atop the 3D MEA for 28 Days in vitro (DIV). Herein, we present results of the fabrication technology including AFM profilometry of interconnects, in addition to Impedance Spectroscopy, Root Mean Square (RMS) noise characterization, mechanical stability of the MEAs and long-term culture viability of the integrated tissue chip (Nerve-on-a-Chip ^® construct on the 3D MEAs) with fluorescence imaging.