面向微流控封装应用的PDMS表面无裂纹改性

Modification Research on Polydimethylsiloxane(PDMS)Surface without Cracks for Applications of Microfluidic Package

基于PDMS的微流控系统的键合封装技术需要PDMS表面具有良好的粘合力和亲水性,作为PDMS表面改性技术,等离子体处理工艺(Plasma)具有高效、快捷、操作简单等特点,但它存在"回复"和裂纹问题。文中介绍了一种结合Plasma和表面活性剂十二烷基硫酸钠(SDS)的二次处理工艺。先利用Plasma技术对PDMS表面进行无裂纹亲水处理,再利用十二烷基硫酸钠溶液对其表面进行二次处理。既可以避免PDMS表面出现裂纹,又可以使PDMS表面亲水性长久的保持。通过实验验证,两次处理后接触角减小为21°,表面粗糙度达到1.71 nm,且表面无裂纹,并经过键合测试后,经过二次处理的PDMS与玻璃和PDMS实现了长久的键合,验证了该工艺技术可行,为微流控系统的键合封装提供了技术基础。

The bonding packaging technology based on polydimethylsiloxane（PDMS） microfluidic system needs good adhesion and hydrophilicity in the surface of PDMS. As PDMS surface modification technology,plasma treatment process（Plasma） has many characteristics,such as high efficiency,high speed and easy operation,but this technology has the problems of＂reply＂and＂crack＂. A secondary treatment process combined with Plasma technology and SDS was introduced in this paper. First,we made hydrophilic treatment without cracks on the PDMS surface using Plasma technology,then made secondary treatment with sodium dodecyl sulfate（SDS）. This can not only avoid the cracks of PDMS surface,but also make the PDMS surface hydrophilic permanently. Through experiments,the contact angle decreases to 21 ° after re-treatment,the roughness of the surface reaches to1. 71 nm,and no crack is on the surface. After bonding test,PDMS after re-treatment can bond with glass permanently,which verifies the feasibility of the technology and lays the technical foundation for the bonding package of microfluidic systems.