High-density stretchable microelectrode array based on multilayer serpentine interconnections

Microelectrode array (MEA) is a powerful tool for recording electrophysiological signals and studying the electrophysiological features of nerve, retina, and cardiomyocytes. Stretchable electrodes can form conformal contact with dynamic biological tissues/organs (e.g. heart) to enhance the coupling efficiency in electrophysiological measurements. However, MEAs based on conventional materials require serpentine interconnections to enable stretchability. A large number of serpentine interconnects take up spaces and hinder the improvement of spatial resolution. Here, we introduce a multilayer design strategy that yields a stretchable MEA with spatial density of 7.3 sites mm(-2) and biaxial stretchability of 30%. The serpentine interconnects of each layer overlap vertically to reduce the area of the wires used for connection. In vitro validation in phosphate buffered saline and ex vivo test on perfused mouse heart show a 100% yield rate of the multilayer stretchable MEA, with capabilities in spatiotemporal mapping of electrophysiological signals at high spatial resolution.