The enhanced wetting property of silicon mesh microchannels coated with SiO2/SnO2 nanoparticles is presented in this paper. The SiO2/SnO2 bi-layers are prepared using layer-by-layer nano self assembly. It is found that the silicon mesh microchannels are super hydrophilic and demonstrated powerful capillary. The capillary rise rate is characterized by measuring the front location of liquid on the silicon mesh surface, laid on a 45° inclined platform. For a silicon mesh sample with an overall dimension of 25 mm × 25 mm, when the microchannel width is 0.5 mm, the liquid front can reach the top edge of the sample in approximately 30 s. The mesh silicon surface with a SiO2/SnO2 multilayer film presented in this paper has better wettability and higher capillary pressure than other hydrophilic surfaces reported. The results provide a new way to improve the capillary in microchannels with enhanced super hydrophilic surfaces in microchannels for variety of micro/nanofluidic applications.
Bibliographical noteFunding Information:
We are grateful to the Nanofabrication Center and Characterization Facility at the University of Minnesota for their help with fabrication and characterization. Tao Zhang He received his Ph.D. degree in mechanical engineering from Chinese Academy of Sciences, China, in 2007. He joined Prof. Tianhong Cui's group at the University of Minnesota in 2008. Currently, he works as a post-doctoral associate in the Department of Mechanical Engineering at the University of Minnesota. His research interest includes micro/nanofabrication, microfluidics, and surface modification. Tianhong Cui received his B.S. degree from Nanjing University of Aeronautics and Astronautics in 1991, and Ph.D. degree from the Chinese Academy of Sciences in 1995. He is currently a Professor of Mechanical Engineering at the University of Minnesota. From 1999 to 2003, he was an assistant professor of electrical engineering at Louisiana Technical University. Prior to that, he was a STA fellow at the National Laboratory of Metrology, and served as a postdoctoral research associate at the University of Minnesota and Tsinghua University. He received research awards including the Nelson Endowed Chair Professorship from the University of Minnesota, the Research Foundation Award from Louisiana Tech University, the Alexander von Humboldt Award in Germany, and the STA & NEDO fellowships in Japan. His current research interests include MEMS/NEMS, nanotechnology, and polymer electronics.
- Layer-by-layer nano self assembly
- Wetting property