Study of plasma treatment for PDMS surface modification on the fabrication of microfluidic devices

Microfluidics is an emerging field that has given rise to a large number of scientific and technological developments over the last few years. The materials that have been employed for the construction of microfluidic devices have been diverse, ranging from traditional materials, such as silicon and glass, to newer polymeric materials. For instance, by using plasma technology, a microfluidic PDMS can be made to have a hydrophilic characteristic on its layer. PDMS is commonly used as microfluidic devices owing to its prominent properties such as transparency, biocompatibility, and cost effectiveness. Various shapes of electrodes in this work were prepared by directly firing the plasma through a specified layer region for duration of 1 to 3 mins. The contact angle was measured using a digital microscope on the specified layer region. The lowest contact angle was achieved in the case of wire-like electrodes in which it was measured to be 28.07°, substantially lower than those obtained in the cases of normal (56.42°) and hollow (33.25°) shapes for the same duration of plasma treatment (3 mins).