Publications – 2026

We present a simple and robust strategy for improving the signal levels of microelectrode array (MEA) recordings from cultures of electrically excitable cells through the engineering of the dielectric surface surrounding the electrodes. A patterned two-component self-assembled monolayer (SAM)–cell membrane interface introduced onto this dielectric surface improves the seal impedance between the cell and MEA, increasing the amplitude of the recorded signals to more closely approach intracellular potentials. Application of this technique to cardiomyocytes derived from human induced pluripotent stem cells (iPSC) results in an almost 3-fold improvement in intracellular-like recording yield compared to traditional Matrigel coatings and a 3-fold increase in signal amplitude compared to a single-component SAM. This technique is simple to translate to most commercial and custom MEAs, including high-density complementary metal-oxide-semiconductor (CMOS) MEAs, and can be easily combined with nanowires, micromushrooms, and optimized electroporation sequences for further signal-level enhancements.

Light-based neuromodulation increasingly demands tools that deliver high spatial and temporal resolution, especially for precise stimulation in deep brain regions. OLEDs are uniquely suited for this purpose due to their ultrathin, conformable architecture and compatibility with flexible substrates and CMOS backplanes. Depending on the characteristics of the probe, OLED pixels can be arranged in high-density, arbitrarily shaped, and individually addressable patterns to be tailored to specific experimental requirements. We demonstrate the monolithic integration of blue and orange top-emitting OLEDs on CMOS chips with four shanks (6 mm long, 150 μm wide), containing a total of 1024 pixels (19×21 μm², 24.5 μm pitch). Using plasma-based surface treatment, we achieve >90% yield and emission levels exceeding 0.2 mW/mm²—sufficient for in vivo single-neuron stimulation. This marks a significant step toward chronic, high-density optoelectronic neural interfaces. Additionally, I will present ongoing work adapting the OLED fabrication process to flexible polyimide-based probes and wireless magnetoelectric substrates, broadening the application scope of OLEDs in implantable neurotechnologies.