Laser Interference Micro- and Nanofabrication of Water Repellent Structures on Stent Surfaces
L-Y. Gao, W-Q. Zhou, Y-B. Wang, S-Q. Wang, C. Bai, S-M. Li, B. Liu, J-N. Wang and Y-L Li
In order to solve the long-term restenosis and the late stent thrombosis, which usually occurs after coronary stent implantation, stent surfaces were directly modified by laser interference lithography and the highly ordered concave structures were fabricated. The morphology and contact angle of the microstructure were measured with scanning electron microscopy and contact angle system. The water repellent property of the stent was also evaluated by the method of contacting the water drop with the stent and then separating. The results show that the close-packed concave structure with the period of 12.194 μm can be fabricated on the stent surface under special parameters (incident angles of 3.0°, laser energy density of 2 J/cm2, exposure time of 90 seconds) by the three beam laser interference of 1064 nm and the form structure has good water repellency with contact angle of 120.5°.
Keywords: Nd:YAG laser, stent, microfabrication, nanofabrication, laser interference lithography, water repellent, restenosis