镍基阵列微针的薄胶微电铸制备工艺OA北大核心CSTPCD

With the advantages of high mechanical strength and good electrical conductivity,Ni micronee-dle arrays are widely used in bioengineering and other fields.By virtue of the advantages of high replication accuracy and wide adaptability,the microelectroforming technique has become a reliable method for prepar-ing Ni microneedles.However,it is usually necessary to use photoresist template with the same thickness as that of the casting layer in the microelectroforming technique.Thick photoresist microelectroforming faces problems such as residual photoresist at the microstructure,difficulty in removing the photoresist.In order to solve the above problems,obtain Ni microneedle arrays with tip curvature radius on the nanome-ter scale,the fabrication process for Ni microneedle arrays based on the thin photoresist microelectroform-ing technique was designed and experimentally verified.First,a silicon template with arrays of pits was fabricated on(100)single crystal silicon wafers.Next,a Ni seed layer with a thickness of 200 nm was sputtered onto the surface of the silicon template.Then,a thin photoresist template of the microneedle support beam was prepared using the photolithography technique.Finally,Ni microneedle arrays were re-leased after microelectroforming.The experimental results show that Ni microneedle arrays with an aver-age deviation in size of 1.7 μm,an average deviation in absolute position of 1.8 μm,and an average curva-ture radius of 150 nm at the tip were obtained by this method without damaging the silicon template.Using RFJ-60 negative photoresist as a template for microelectroforming with a thickness of-2 μm,microneedle support beams with a thickness of-24.3 μm were successfully prepared.Ni microneedle relative dimen-sional error was reduced to 1%by compensating SiO2 lateral erosion into lithographic mask.Combining the microelectroforming technique and the anisotropic etching property of monocrystalline silicon,the Ni microneedle array can be prepared with high quality and high efficiency,which lays the foundation for the batch preparation of Ni microneedle arrays.