Multilevel Microchannel-based, 3D Printed and Liquid-Metal Filled Microelectrode Array Within a Multiphase Controlled Microchamber for Electrophysiological Studies

This paper reports for the first time a monolithically 3D printed array of microchannels in a multilayer circuit with an integrated microchamber. Microchannels at different levels serve as conduits towards a centrally located 2.5D/3D Microelectrode Array (MEA) for electrical stimulation/recording of electrogenic spheroids, and as inlet/outlet for injection/suction of liquids (e.g., samples, reagents). The microchamber allows for control and isolation of the cultured microenvironment, and additionally perfusion of gases (e.g., O
2
, CO
2
) for electroactive responses. The device was characterized with synthetic organoids under Phosphate Buffer Saline (PBS) and sample gas (Oxygen) injection. Impedance responses to the changing microenvironment were studied as was multi-metallic sheet resistance. Barrier integrity and coverage of synthetic organoids matrix are also determined from frequency analysis.