Debris-free Femtosecond Laser Micromachining of Stainless Steel Vascular Stent

doi:10.3901/JME.2021.05.251

Abstract

Abstract: Percutaneous coronary intervention (PCI) implantation of the stent is the main method to resolve the cardiovascular blockage. Nanosecond laser-based micromachining of the stent mesh on the microtube exists some problems such as large thermal effect, slag residue and complex post-treatment. An infrared femtosecond laser with high pulse repetition rate is proposed to machine the stainless-steel scaffolds. The femtosecond laser ablation mechanism, the removal process of materials, and the influence rule of laser fluence, feed speed, pulse repetition rate on the processed surface quality are studied respectively. The results present that femtosecond laser machining with high pulse repetition rate and low laser fluence has good surface quality and processing efficiency. Under the laser parameter combinations of laser fluence of, pulse repetition rate of 100 kHz, feeding speed of 24.6 mm/min and 1.99 J/cm², air gas pressure of 0.1MPa, high-quality vascular scaffolds without re-solidified layer, residual debris and small heat affected zone are obtained. In addition, drug storage holes with a diameter of 30µm were successfully fabricated on the surface of vascular stent.

Key words: femtosecond laser, vascular stent, mechanism, processing parameters, influence rule

CLC Number:

TG665

XIE Xiaozhu, ZHU Yiliang, HUANG Yajun, SHEN Chao, PENG Qingfa, WANG Pengchao, LONG Jiangyou. Debris-free Femtosecond Laser Micromachining of Stainless Steel Vascular Stent[J]. Journal of Mechanical Engineering, 2021, 57(5): 251-261.

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