超声电铸提高金属微流控芯片模具的均匀性

Improvement of microfluidic chip mould thickness uniformity by ultrasonic agitation during electroforming process

利用微电铸技术制作的微流控芯片模具往往存在沉积厚度不均匀的缺陷,这种缺陷会影响模具的尺寸精度及使用性能,并增加模具的制作成本。为了制得厚度均匀的微流控芯片模具,研究了超声电铸对模具均匀性的影响。首先,采用有限元软件COMSOL Multiphysics建立微流控芯片模具的微电铸模型,分析电铸2h后的模具的厚度分布。并根据该仿真结果,设计掩模版。然后,在自主搭建的超声电铸装置中进行一系列电铸实验,来研究超声搅拌对模具均匀性的影响。实验结果表明:电铸过程中添加超声搅拌可以改善微流控芯片模具的均匀性。超声功率为200 W时,超声频率改善模具均匀性的程度为200kHz>80kHz>120kHz。超声频率为200kHz时,超声功率改善模具均匀性的程度为500 W>200 W>100 W。当超声的频率和功率分别为200kHz和500 W时,与无超声电铸相比,模具的均匀性提高约30%。

The electroforming microfluidic chip mould faces the problem of uneven thickness, which influences the dimen-sional accuracy and performance of the mould, and increases the production cost. With the aim of fabricating a microfluidic chipmould with uniform thickness, electroforming with ultrasonic agitation is investigated to improve the thickness uniformity of themould. Firstly, numerical simulation is performed using COMSOL multiphysics software to analyze the thickness distribution ofthe mould after 2 h electroforming. And based on the simulation result, a photomask is designed. Secondly, with the photomask,electroforming experiments are carried out to study how ultrasonic agitation affects the thickness uniformity of the mould. It isfound that the ultrasonic agitation can improve the thickness uniformity of the mould. With 200 W ultrasonic agitation, the effectof ultrasonic frequency on the thickness uniformity increases in the order of 200 kHz〉80 kHz〉120 kHz. And with 200 kHz ul-trasonic agitation, the effect of ultrasonic power on the thickness uniformity increases in the order of 500 W〉200 W〉100 W.Compared with the thickness uniformity without ultrasonic agitation, with 200 kHz and 500 W ultrasonic agitation, the thicknessuniformity of the mould is increased by about 30%.