Effects of Micro-Milling and Laser Engraving on Processing Quality and Implantation Mechanics of PEG-Dexamethasone Coated Neural Probe

doi:10.1007/s12204-020-2243-7

摘要/Abstract

摘要： Compared with stiff silicon-based probes, flexible neural probes can alleviate biological inflammation and tissue rejection. A polyethylene glycol (PEG) coating can facilitate the insertion of flexible probes, and the fabrication methods have a significant impact on the dimensional accuracy and structural strength of the coating. In this study, a novel melting injection moulding method is used to process a PEG-dexamethasone (PEG-DEX) coating with high structural strength for a type of mesh-shaped photosensitive polyimide (PSPI) based neural probe. Combined with the digital image correlation (DIC) method, an in vitro test system with high accuracy is developed to evaluate the effects of the elastic modulus of the PEG component and two fabrication methods, i.e., computer-numerical-control (CNC) micro-milling and laser engraving, on the processing quality and implantation mechanics of a PEG-DEX coated probe. The results show that compared with laser engraving, CNC micro-milling can ensure high dimensional accuracy and sharpness for the composite coating, thus leading to small damage from implantation, whereas the elastic modulus of the composite coating has a limited effect on the implantation mechanics of the PEG-DEX coated probe.

关键词: flexible neural probe, composite coating, digital image correlation (DIC), polyethylene glycol (PEG), dexamethasone (DEX), insertion force, implantation injury

Abstract: Compared with stiff silicon-based probes, flexible neural probes can alleviate biological inflammation and tissue rejection. A polyethylene glycol (PEG) coating can facilitate the insertion of flexible probes, and the fabrication methods have a significant impact on the dimensional accuracy and structural strength of the coating. In this study, a novel melting injection moulding method is used to process a PEG-dexamethasone (PEG-DEX) coating with high structural strength for a type of mesh-shaped photosensitive polyimide (PSPI) based neural probe. Combined with the digital image correlation (DIC) method, an in vitro test system with high accuracy is developed to evaluate the effects of the elastic modulus of the PEG component and two fabrication methods, i.e., computer-numerical-control (CNC) micro-milling and laser engraving, on the processing quality and implantation mechanics of a PEG-DEX coated probe. The results show that compared with laser engraving, CNC micro-milling can ensure high dimensional accuracy and sharpness for the composite coating, thus leading to small damage from implantation, whereas the elastic modulus of the composite coating has a limited effect on the implantation mechanics of the PEG-DEX coated probe.

Key words: flexible neural probe, composite coating, digital image correlation (DIC), polyethylene glycol (PEG), dexamethasone (DEX), insertion force, implantation injury

中图分类号:

R 318.01

ZHOU Xuhui (周旭辉), ZHANG Wenguang (张文光), XIE Jie (谢颉). Effects of Micro-Milling and Laser Engraving on Processing Quality and Implantation Mechanics of PEG-Dexamethasone Coated Neural Probe[J]. J Shanghai Jiaotong Univ Sci, 2021, 26(1): 1-9.

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