[Sensors and Actuators B: Chemical] Silicon based solvent immersion imprint lithography for rapid po
Polystyrene (PS) is preferred over polydimethylsiloxane (PDMS) in microfluidics for applications in cell biology. However, PS has not found widespread use in microfluidics due mainly to the lack of rapid prototyping techniques. Here we address this issue by developing a silicon based solvent immersion imprint lithography (Si-SIIL) technique. Silicon is rigid, mechanically robust, and highly compatible with standard microfabrication processes, and therefore, is a promising candidate for molds. Various PS microfluidic channels as small as 20 μm in width with the aspect ratio as high as 5 were demonstrated using Si-SIIL. Bubbles and bending generated in the fabrication process were analyzed and eliminated. The surface roughness was about 27 nm (rms). Compared to the untreated PS, the molded PS retained almost the same surface properties, as characterized by contact angle measurement and X-ray photoelectron spectroscopy. Cell culture was tested to demonstrate the utility of Si-SIIL in cell biology applications. The results show that PS, with the aid of Si-SIIL, can be an alternative material to PDMS in building microfluidic chips.
Jingdong Chen a, Wenjie Wang a, Weibang Ji a, Shaoding Liu a, Qiushu Chen b, Bimin Wu b, Rhima Coleman b, Xudong Fan a, b, , a Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, College of Physics and Optoelectronics, Taiyuan University of Technology, 79 Yingze Street, Taiyuan 030024, PR China b Department of Biomedical Engineering, University of Michigan, 1101 Beal Avenue, Ann Arbor, Michigan 48109, USA Received 12 December 2016, Revised 24 March 2017, Accepted 28 March 2017, Available online 30 March 2017 Show less http://dx.doi.org/10.1016/j.snb.2017.03.146