Prototyping of a Stretchable Microelectrode Array for Cardiotoxicity Drug Screening

Abstract

Cardiotoxicity is a common side-effect of drugs and a major cause of late-stage drug rejections, costing the pharmaceutical companies massive amounts of money. A drug is cardiotoxic when it has a negative influence on the heart. Often, it changes the electrophysiological characteristics of the heart, resulting in arrhythmia. This can have potentially fatal consequences. Thus, it would be desirable to have a reliable, early-stage indicator of the cardiotoxicity of a drug. A stretchable microelectrode array probing the electrophysiology of cardiomyocytes under influence of a drug could be a big improvement in cardiotoxicity drug screening. It has two advantages over current systems employing human embryonic stem cell (HESC)-derived cardiomyocytes. It allows anisotropic contraction of the heart cells, mimicking a real heart more closely, and it could train the cardiomyocytes; both primarily due to the stretchable nature of the device. A prototype of a stretchable MEA was designed, using the silicone elastomer PDMS as stretchable substrate and wavy gold tracks as stretchable conductors. The device consists of the following basic parts: - Support - Patterned release layer - Stretchable substrate - Electrodes - Interconnect - Patterned insulation layer - Container for nutritious solution - Cell pattern A process flow was developed to fabricate the device. The device could almost be fully fabricated. The only problem that was not solved was the failure to contact the bond pads. There was no time left to test and characterize the device.