Wang Minjie, Zhang Yuan, Bin Jianxiong, Niu Lan, Zhang Jing, Liu Lusheng, Wang Aiping, Tao Jin, Liang Jingqiu, Zhang Lihua, Kang Xiaoyang
Laboratory for Neural Interface and Brain Computer Interface, Engineering Research Center of AI & Robotics, Ministry of Education, Shanghai Engineering Research Center of AI & Robotics, MOE Frontiers Center for Brain Science, State Key Laboratory of Medical Neurobiology, Institute of AI and Robotics, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China.
Ji Hua Laboratory, Foshan 528200, China.
Micromachines (Basel). 2022 Sep 7;13(9):1484. doi: 10.3390/mi13091484.
PDMS (polydimethylsiloxane) is an important soft biocompatible material, which has various applications such as an implantable neural interface, a microfluidic chip, a wearable brain-computer interface, etc. However, the selective removal of the PDMS encapsulation layer is still a big challenge due to its chemical inertness and soft mechanical properties. Here, we use an excimer laser as a cold micro-machining tool for the precise removal of the PDMS encapsulation layer which can expose the electrode sites in an implantable neural interface. This study investigated and optimized the effect of excimer laser cutting parameters on the electrochemical impedance of a neural electrode by using orthogonal experiment design. Electrochemical impedance at the representative frequencies is discussed, which helps to construct the equivalent circuit model. Furthermore, the parameters of the equivalent circuit model are fitted, which reveals details about the electrochemical property of neural electrode using PDMS as an encapsulation layer. Our experimental findings suggest the promising application of excimer lasers in the micro-machining of implantable neural interface.
聚二甲基硅氧烷（PDMS）是一种重要的具有生物相容性的软材料，它有多种应用，如可植入神经接口、微流控芯片、可穿戴脑机接口等。然而，由于其化学惰性和柔软的机械性能，选择性去除PDMS封装层仍然是一个巨大的挑战。在此，我们使用准分子激光作为冷微加工工具，精确去除PDMS封装层，从而在可植入神经接口中暴露电极位点。本研究通过正交实验设计，研究并优化了准分子激光切割参数对神经电极电化学阻抗的影响。讨论了代表频率下的电化学阻抗，这有助于构建等效电路模型。此外，对等效电路模型的参数进行了拟合，揭示了以PDMS作为封装层的神经电极的电化学特性细节。我们的实验结果表明准分子激光在可植入神经接口的微加工中具有广阔的应用前景。
