Work

Advanced Micro‐OLED Integration on Thin and Flexible Polymer Neural Probes for Targeted Optogenetic Stimulation

Year: 2025

Type: article

Abstract: In recent optogenetics, flexible neural probes with integrated high‐resolution light sources are needed for precise neural circuit analysis. This paper presents a novel flexible neural probe with integrated micro‐Organic Light Emitting Diode (OLED)s for the first time. Eight micro‐OLEDs (sizes ranging from 10 × 10 µm2 to 100 × 100 µm2) and eight recording electrodes are integrated on a flexible SU‐8 substrate, allowing for simultaneous optical stimulation and neural activity recording. An advanced micro‐OLED integration process, utilizing Al₂O₃/parylene‐C encapsulation, achieves a low water vapor transmission rate of 2.66 × 10⁻⁵g m−2 day−1, enhancing durability. An indium zinc oxide (IZO)/silver (Ag)/indium zinc oxide (IZO) structure, referred to as an IAI anode, is introduced to improve OLED performance, and a parylene‐C pixel defining layer minimizes crosstalk and enables independent pixel operation. The micro‐OLEDs emit light at 470 nm, suitable for activating channelrhodopsin‐2 (ChR2), with sufficient optical power density (1 mW mm−2 at 15 V) confirmed through integrating sphere measurements. This innovative OLED probe represents a significant advancement in optogenetics, providing localized high‐resolution stimulation and electrical recording with minimal invasiveness.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202420758