Chen Zhiyuan, Yin Rose T, Obaid Sofian N, Tian Jinbi, Chen Sheena W, Miniovich Alana N, Boyajian Nicolas, Efimov Igor R, Lu Luyao
Department of Biomedical Engineering, The George Washington University, Washington, DC 20052, USA.
Adv Mater Technol. 2020 Aug;5(8). doi: 10.1002/admt.202000322. Epub 2020 Jun 3.
Flexible and transparent microelectrodes and interconnects provide the unique capability for a wide range of emerging biological applications, including simultaneous optical and electrical interrogation of biological systems. For practical biointerfacing, it is important to further improve the optical, electrical, electrochemical, and mechanical properties of the transparent conductive materials. Here, high-performance microelectrodes and interconnects with high optical transmittance (59-81%), superior electrochemical impedance (5.4-18.4 Ω cm), and excellent sheet resistance (5.6-14.1 Ω sq), using indium tin oxide (ITO) and metal grid (MG) hybrid structures are demonstrated. Notably, the hybrid structures retain the superior mechanical properties of flexible MG other than brittle ITO with no changes in sheet resistance even after 5000 bending cycles against a small radius at 5 mm. The capabilities of the ITO/MG microelectrodes and interconnects are highlighted by high-fidelity electrical recordings of transgenic mouse hearts during co-localized programmed optogenetic stimulation. histological analysis reveals that the ITO/MG structures are fully biocompatible. Those results demonstrate the great potential of ITO/MG interfaces for broad fundamental and translational physiological studies.
柔性且透明的微电极和互连结构为广泛的新兴生物应用提供了独特的能力，包括对生物系统进行光学和电学的同步检测。对于实际的生物接口而言，进一步改善透明导电材料的光学、电学、电化学和机械性能非常重要。在此，展示了使用氧化铟锡（ITO）和金属网格（MG）混合结构的高性能微电极和互连结构，其具有高光学透过率（59 - 81%）、优异的电化学阻抗（5.4 - 18.4 Ω·cm）和出色的薄层电阻（5.6 - 14.1 Ω/sq）。值得注意的是，这种混合结构保留了柔性MG的优异机械性能，不同于脆性的ITO，即使在以5毫米的小半径进行5000次弯曲循环后，薄层电阻也没有变化。在共定位的程控光遗传学刺激过程中，对转基因小鼠心脏进行高保真电记录突出了ITO/MG微电极和互连结构的能力。组织学分析表明ITO/MG结构具有完全的生物相容性。这些结果证明了ITO/MG接口在广泛的基础和转化生理学研究中的巨大潜力。
