Microelectrode Arrays for Dropletronic Circuits

Iontronics is emerging as a promising approach for neuromorphic computing. Among various iontronic device architectures, researchers have used droplet assemblies to implement synaptomimetic functionalities. However, most reported devices rely on a two-droplet architecture. Here, we introduce microfabricated microelectrode arrays (MEAs) to enable a scalable droplet-based iontronic circuit, termed a dropletronic circuit. The MEAs are fabricated in the cleanroom using standard microelectromechanical systems (MEMS) techniques and consist of platinum tracks, a SiO2 insulating layer, and an SU-8 confinement structure. The electrodes are characterized in phosphate-buffered saline (PBS), and surface wettability is assessed to ensure reliable operation. Moreover, electrochemical measurements in oil with droplet interface bilayers (DIBs) demonstrate favorable properties. Our platform represents a step toward achieving reservoir computing with arrays of dropletronic circuits.