Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices | Mukhopadhyay et al. Nanoscale Research Letters 2011 6 411 http content 6 1 411 o Nanoscale Research Letters a SpringerOpen Journal NANO IDEA Open Access Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices Subhadeep Mukhopadhyay Susanta S Roy Raechelle A D Sa Ashish Mathur Richard J Holmes and James A McLaughlin Abstract Polymethylmethacrylate PMMA microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon DLC film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from to when compared to pristine PMMA surfaces. Additionally capillary flow of water dyed to aid visualization through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle and also that the incorporation of micropillars into a fluidic device increases the filling time when compared to comparative devices. Introduction In recent years microfluidics has become an indispensable component of microelectromechanical systems MEMS technology 1-3 with polymer devices establishing a greater role in the development of disposable microfluidic systems 4 . One such polymer is polymethylmethacrylate PMMA which is used in the fabrication of a wide variety of microfluidic devices 4 5 from micro-reactors 4 to .
