Application of a PDMS microstencil as a replaceable insulator toward a single-use planar microelectrode array

Here we present a novel idea for a replaceable insulator, and thus advance toward the goal of a single-use planar microelectrode array (MEA) for the study of electrogenic tissues. The concept of a replaceable insulator is motivated by insulator degradation after repeated usage of an MEA. Instead of fabricating a more durable insulator for repeated MEA usage, we propose replacing the insulator and effectively producing a fresh MEA for each experiment. We chose a polydimethylsiloxane (PDMS) microstencil as a candidate for the replaceable insulator as it is biocompatible, shows reversible adhesion to surfaces, and can be easily and controllably fabricated. As a proof-of-concept, we demonstrate two applications using microstencils: the rejuvenation of an old MEA and the fabrication of a single-use MEA. These MEAs were tested with dissociated neural cell cultures and neural recordings were performed at 14 days in vitro. Inexpensive and quick supply of insulators with micrometer-sized holes provides a way of constructing an MEA that can be treated as a disposable component in high throughput cell-based biosensor applications.