High-definition microelectrode arrays with scalable, integrated microfluidics in multi-well format for drug screening in a heart-on-a-chip application

Towards increased throughput and automated workflows for organs- on-a-chip, a novel high-definition electrophysiology multiwell plate is developed in the Moore4Medical project [1]. It consists of an advanced CMOS microelectrode array (MEA) chip with 16 sampling areas, each featuring 1024 electrodes [2], and of a polymeric fluidic cartridge with 16 corresponding microchambers, each connected to an integrated pneumatic peristaltic pump [3]. It can perform 16-well assays with single-cell-resolution electrical recording and integrated microfluidics. Building on an earlier prototype, we present recent developments showing a scalable integration route and excellent fluidic and electrical functionalities of the plate in an easy-to-use system. Direct bonding of the MEA chip and the cartridge was achieved using accurate glue deposition and a high-precision pick-&-place procedure, resulting in 16 well-aligned, sealed microchambers on top of the MEA. This method is developed for high-volume production. To run the plate, a user-friendly toolbox, which can be placed inside an incubator, is made together with a data acquisition unit, a pneumatic control unit, and custom software. The plate can be clamped directly inside the toolbox, ensuring communication of the MEA with the data acquisition unit by a pogo-pin connection. The pneumatic control unit actuates the 16 integrated pumps simultaneously via three pressure lines. Hence, 16 assays can run in parallel, with simple pipetting steps for cell seeding and media perfusion. To demonstrate the plate’s functions, all the 16 microchambers were primed and filled with water and 1% PBS buffer sequentially. No liquid leakage or bubble entrapment was observed. The voltage scan of the 16 MEA areas showed uniform signals and a clear difference between the two liquids (0.08 mVrms for water; 0.02 mVrms for PBS). Plate biological-validation is currently on-going to study the effect of drugs on electrical and contractile properties of human stem-cell derived cardiomyocytes and to demonstrate the plate potential for OoC standardization and workflow streamlining.