基于硅与非硅复合方法的异平面空心微针制作

Out-of-Plane Hollow Microneedles Fabricated by Combining Silicon and Non-Silicon Method

为了解决制备空心微针工艺复杂且成本高的问题,本文提出了采用湿法刻蚀、光刻和电镀结合的方法制备低成本空心金属微针.首先采用湿法刻蚀硅,得到280μm深的倒四棱锥锥坑;然后在锥坑上甩200μm厚的负胶SU-8填充锥坑,并通过曝光显影负胶形成微针的形貌;最后在曝光显影后的负胶上电镀50μm厚的镍得到所需形状的空心金属微针.用此方法制备的空心微针高度为350μm、壁厚为50μm,其针尖形状为三棱锥和四棱锥.通过有限元仿真分析微针强度与微针结构尺寸的关系.用此方法加工出的微针具有锥形尖,改善了刺入皮肤的效果.

In order to solve the problem of hollow microneedles which have high cost and complex fabrication processes, a low-cost fabrication method of hollow metallic microneedles, which uses wet etching, lithography and electroplating technology to form microneedles, was proposed in this paper. First, the silicon wafer was etched by wet etching to form inverted pyramid cavities with 280 μm in depth; then the SU-8 with the thickness of 200 μm was spun in the cavities and was developed to pattern the shape of microneedles; finally, the nickel with 50 μm was electroplated on the patterns to get hollow metallic microneedles. These microneedles are about 350 μm in length, about 50μm in wall thickness. The tip shapes of the microneedles are third pyramid, fourth pyramid. Also, FEM is used to analyze the relationship between microneedle force and their structures. This method can get low-cost microneedles. In addition, these mieroneedles have pyramid tip, which helps improving their penetrability in the skin.