基于LIGA技术制作金属微针阵列

MEMS微针在生物领域中的应用日益广泛,为了方便微针刺入皮肤且减少疼痛,要求微针具有足够的强度和锐利的尖端。传统LIGA工艺只能制造出具有高深宽比的垂直侧壁结构。对传统LIGA工艺进行调整,对光刻胶PMMA进行两次曝光,并通过移动光刻胶台改变X射线的光刻方向,使两次X射线曝光方向相垂直,提出移动LIGA工艺,即移动光刻工艺。此外,利用等腰三角形作为掩膜板图案,显影之后得到截面与X射线掩膜板图案相似的三维实心PMMA微针阵列。再利用此PMMA微针阵列作为原始模具,PDMS转模形成PDMS一级模具,电镀镍得到与PMMA微针阵列相似的金属镍微针阵列。

Metal Micro Needle Arrays Based on the LIGA Technology

MEMS micro needles are becoming widely used in the biomedical field.In order to pe-netrate the skin easily and reduce the pain,enough stiffness and sharp tip are needed.However,only micro structures of the vertical sidewalls were obtained employing the conventional LIGA technology.To obtain the beveled sidewalls,some processes were improved and the moving LIGA technology was proposed,i.e.dragging lithography process.Compared to the LIGA techno-logy,the PMMA was exposed by X-ray twice and the second exposure was perpendicular to the first one through turning the resist stage during the second exposure.With the isosceles triangle mask pattern,the 3-dimensinal solid PMMA micro needle arrays with pyramids-like sidewalls were fabricated based on the dragging LIGA technology.Besides that,the cross section of the micro needles was similar to the X-ray mask pattern.Then the first mold of the PDMS micro needle arrays were fabricated with the PMMA micro needle arrays as the original mold,and finally the metallic micro needle arrays were fabricated with the electronickelling by PDMS mold,which were similar to the PMMA micro needle arrays.