Optical microelectrode arrays for differential readout of electrical and mechanical signals in cardiac cells

Abstract

Simultaneous assessment of electrical excitation and mechanical contraction is essential for understanding cardiac cell function, yet these two processes are commonly measured with separate techniques or invasively. Here, changes in cellular electrical activity modulate local charge redistribution in optical microelectrodes and are converted into fluorescence signals, while cell contraction induces membrane displacement that contributes an additional mechanical component to the optical readout. By comparing recordings obtained in beating cells with those acquired after inhibition of contraction, we separate action-potential-associated electrostatic transduction from contractility-driven membrane motion. The approach offers a label-free route to support high-throughput in vitro assays for cardiotoxicity screening and electromechanical sensing. Concurrently, it unfolds the physical mechanisms governing membrane-based optical devices deployed in cardiac cell bioelectronics and mechanics.