Antonini Marc-Joseph, Sahasrabudhe Atharva, Tabet Anthony, Schwalm Miriam, Rosenfeld Dekel, Garwood Indie, Park Jimin, Loke Gabriel, Khudiyev Tural, Kanik Mehmet, Corbin Nathan, Canales Andres, Jasanoff Alan P, Fink Yoel, Anikeeva Polina
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Adv Funct Mater. 2021 Oct 20;31(43). doi: 10.1002/adfm.202104857. Epub 2021 Aug 6.
Fiber drawing enables scalable fabrication of multifunctional flexible fibers that integrate electrical, optical and microfluidic modalities to record and modulate neural activity. Constraints on thermomechanical properties of materials, however, have prevented integrated drawing of metal electrodes with low-loss polymer waveguides for concurrent electrical recording and optical neuromodulation. Here we introduce two fabrication approaches: (1) an iterative thermal drawing with a soft, low melting temperature (T) metal indium, and (2) a metal convergence drawing with traditionally non-drawable high T metal tungsten. Both approaches deliver multifunctional flexible neural interfaces with low-impedance metallic electrodes and low-loss waveguides, capable of recording optically-evoked and spontaneous neural activity in mice over several weeks. We couple these fibers with a light-weight mechanical microdrive (1g) that enables depth-specific interrogation of neural circuits in mice following chronic implantation. Finally, we demonstrate the compatibility of these fibers with magnetic resonance imaging (MRI) and apply them to visualize the delivery of chemical payloads through the integrated channels in real time. Together, these advances expand the domains of application of the fiber-based neural probes in neuroscience and neuroengineering.
纤维拉伸能够实现多功能柔性纤维的可扩展制造，这些纤维集成了电学、光学和微流体功能，以记录和调节神经活动。然而，材料热机械性能的限制阻碍了金属电极与低损耗聚合物波导的集成拉伸，无法同时进行电记录和光神经调节。在此，我们介绍两种制造方法：（1）使用柔软、低熔点（T）金属铟的迭代热拉伸，以及（2）使用传统上不可拉伸的高T金属钨的金属收敛拉伸。这两种方法都能提供具有低阻抗金属电极和低损耗波导的多功能柔性神经接口，能够在数周内记录小鼠的光诱发和自发神经活动。我们将这些纤维与一个轻质机械微驱动器（1g）相结合，该微驱动器能够在长期植入后对小鼠的神经回路进行深度特异性询问。最后，我们展示了这些纤维与磁共振成像（MRI）的兼容性，并应用它们实时可视化化学物质通过集成通道的输送。总之，这些进展扩展了基于纤维的神经探针在神经科学和神经工程中的应用领域。
