Resorbable coatings are processed on flexible implants to facilitate penetrations. However, impacts of fabricating methods on implantation damage of coated probes are unclear. Herein, photosensitive polyimide (PSPI) based flexible neural implants are fabricated through clean-room technology. Polyethyleneglycol (PEG) - dexamethasone (DEX) coatings are processed through an improved micro moulding protocol in micro channels, fabricated by computer-numerical-controlled (CNC) micro milling, laser machining, and deep reactive ion etching (DRIE), respectively. An in vitro testing system is developed, using maximum insertion force \({F}_{max}\) and mean region-of-interest strain \({S}_{mean}\) to accurately evaluate effects of the three fabricating methods on implantation damage at different insertion speed. Rat cerebrum, agarose gel, and silicone rubber are used as brain phantoms for tests. Results show that lower insertion speed, and micro channels fabricated by CNC micro milling or DRIE can minimize implantation damage. The decrease of insertion speed from 2.0 mm/s to 0.5 mm/s reduces \({F}_{max}\) by 76.2% ~85.1% and \({S}_{mean}\) by 11.6% ~14.7%, respectively. Compared with laser machining, CNC micro milling and DRIE ensure dimensional accuracy of the PEG/DEX coating, reducing \({F}_{max}\) by 20.2% ~51.4% and \({S}_{mean}\) by 8.0% ~11.6%, respectively. Compared with biological rat cerebrum, \({F}_{max}\) reduces by 5.8% ~25.1% in agarose gel phantom and increases by 7.7% ~21.0% in silicone rubber phantom, respectively. This study improves processing methods of polymer coatings and reveals mechanical difference between current used abiotic brain phantoms and biological brain tissues. Implantation tests establish quantitative relationship among insertion speed, fabricating methods, and implantation damage.

在柔性植入物上加工可吸收涂层以促进渗透。然而，制造方法对涂层探针植入损伤的影响尚不清楚。在此，基于光敏聚酰亚胺 (PSPI) 的柔性神经植入物是通过洁净室技术制造的。聚乙二醇 (PEG) - 地塞米松 (DEX) 涂层在微通道中通过改进的微成型协议进行加工，分别通过计算机数字控制 (CNC) 微铣削、激光加工和深反应离子蚀刻 (DRIE) 制造。开发了体外测试系统，使用最大插入力\({F}_{max}\)和平均感兴趣区域应变\({S}_{mean}\)以准确评估三种制造方法对不同插入速度下植入损伤的影响。大鼠大脑、琼脂糖凝胶和硅橡胶被用作测试的大脑模型。结果表明，较低的插入速度和通过 CNC 微铣削或 DRIE 制造的微通道可以最大限度地减少植入损伤。插入速度从 2.0 mm/s 降低到 0.5 mm/s 使\({F}_{max}\)减少 76.2% ~85.1% 和\({S}_{mean}\)减少 11.6% ~14.7 ％， 分别。与激光加工相比，CNC微铣削和DRIE确保PEG/DEX涂层的尺寸精度，将\({F}_{max}\)降低20.2% ~51.4%和\({S}_{mean}\)分别为 8.0% ~11.6%。与生物大鼠大脑相比，\({F}_{max}\)在琼脂糖凝胶体模中分别减少 5.8% ~25.1% 和在硅橡胶体模中增加 7.7% ~21.0%。这项研究改进了聚合物涂层的加工方法，并揭示了当前使用的非生物脑幻影和生物脑组织之间的机械差异。植入试验建立了植入速度、制造方法和植入损伤之间的定量关系。