高聚物微流控芯片镍阳模的简易加工技术

提出了一种简便快速制作高聚物微流控芯片镍阳模的新方法。采用抛光镍片作为电铸基底,涂覆SU-8光胶层后,光刻得到SU-8微结构。以镍基片作为阳极,用16～30A/dm2的电流密度电解刻蚀5min,清除SU-8微结构间隙底部镍片表面的氧化物,并刻蚀得到10～20μm深的凹坑,有效地提高了随后电沉积镍结构和基底镍片间结合力。利用SU-8微结构作为电铸模板,以镍基片作为阴极,电铸5h后制得了微结构倾角为83°深宽比较大的镍阳模。实现了在普通化学实验室中长寿命镍阳模的制作。用热压法制得500多片聚甲基丙烯酸甲酯(PMMA)聚合物芯片,并成功用于DNA片段的分离。

A Simplified Microfabrication Technology for Production of Nickel Mold Insert for Replicating of Plastic Microfluidic Chips

A simple and inexpensive method to fabricate nickel mold insert for replicating of plastic microfluidic chips has been developed without the requirement of specialized equipments.A polished nickel plate was used as a substrate on which a thick SU-8 photoresist layer was coated.Conventional contact UV lithography was applied to pattern the thick SU-8 photoresist layer.After development,electroetching was conducted at a large current density of 16-30 A/dm2 for 5 min to clean the nickel surface in the SU-8 recesses where unexposed SU-8 had been lifted up and to form 10-20 m depth of root structures for increasing the strength of the nickel insert electroformed later on.By using the fabricated SU-8 microstructure as a template and nickel substrate as an electrode supplying current,nickel mold insert with a sidewall slope of 83 and higher aspect ratio were successfully fabricated within 5 h in a conventional chemical laboratory.More than 500 polymethyl methyl acrylate(PMMA)microfluidic chips have been replicated by hot-embossing.The chips have been used successfully for the separation of DNA fragments.