Almasri Reem M, Ladouceur François, Mawad Damia, Esrafilzadeh Dorna, Firth Josiah, Lehmann Torsten, Poole-Warren Laura A, Lovell Nigel H, Al Abed Amr
Graduate School of Biomedical Engineering, UNSW, Sydney, NSW 2052, Australia.
School of Materials Science and Engineering, UNSW, Sydney, NSW 2052, Australia.
APL Bioeng. 2023 Sep 7;7(3):031503. doi: 10.1063/5.0153753. eCollection 2023 Sep.
Optical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems. This review presents an overview of devices and material systems that utilize light for electrophysiology recording and stimulation. The work focuses on the current and emerging methods and their applications, and provides a detailed discussion of the design and fabrication of flexible arrayed devices. Optrode arrays feature components non-existent in conventional multi-electrode arrays, such as waveguides, optical circuitry, light-emitting diodes, and optoelectronic and light-sensitive functional materials, packaged in planar, penetrating, or endoscopic forms. Often these are combined with dielectric and conductive structures and, less frequently, with multi-functional sensors. While creating flexible optrode arrays is feasible and necessary to minimize tissue-device mechanical mismatch, key factors must be considered for regulatory approval and clinical use. These include the biocompatibility of optical and photonic components. Additionally, material selection should match the operating wavelength of the specific electrophysiology application, minimizing light scattering and optical losses under physiologically induced stresses and strains. Flexible and soft variants of traditionally rigid photonic circuitry for passive optical multiplexing should be developed to advance the field. We evaluate fabrication techniques against these requirements. We foresee a future whereby established telecommunications techniques are engineered into flexible optrode arrays to enable unprecedented large-scale high-resolution electrophysiology systems.
光电极（optrode）阵列利用光来调制可兴奋生物组织和/或将生物电信号转换到光学领域。与电线相比，光具有多个优势，包括能够在单束光中编码多个数据通道。这种方法处于旨在提高多通道电生理系统空间分辨率和通道数量的创新前沿。本综述概述了利用光进行电生理记录和刺激的设备和材料系统。工作重点关注当前和新兴方法及其应用，并详细讨论了柔性阵列设备的设计和制造。光电极阵列具有传统多电极阵列中不存在的组件，如波导、光学电路、发光二极管以及光电和光敏功能材料，以平面、穿透或内窥镜形式封装。这些组件通常与介电和导电结构相结合，较少与多功能传感器结合。虽然制造柔性光电极阵列是可行且必要的，以尽量减少组织与设备之间的机械不匹配，但在监管批准和临床使用时必须考虑关键因素。这些因素包括光学和光子组件的生物相容性。此外，材料选择应与特定电生理应用的工作波长相匹配，在生理诱导的应力和应变下尽量减少光散射和光学损耗。应开发传统刚性光子电路的柔性和软性变体用于无源光复用，以推动该领域发展。我们根据这些要求评估制造技术。我们预见未来会将成熟的电信技术应用于柔性光电极阵列，以实现前所未有的大规模高分辨率电生理系统。
