Controlled anisotropic wetting on silicon nanaogrooves and the application to BioMEMS

Abstract

This research investigates modification methods for controlling anisotropic wetting, using silicon nanostructures. This research studies structural and chemical approaches respectively and shows the possible applications of each. Finally the two methods are integrated and the study discusses the effect of the combination. In the first part, anisotropic wetting characteristics of scalloped nanogrooves (SNGs) are investigated, which is a structural modification. The SNGs having various scallop edge angles are fabricated by Bosch deep reactive ion etching (DRIE). Wetting properties of the nanopatterned surfaces are studied in dynamic and stat-ic regimes. Anisotropic wettability of the SNGs is successfully utilized for controlling fluid flows in microflu-idic channels. In the second part, chemical modification of silicon nanogrooves (NGs) for controlling anisotropic wetting is studied. By precise control of self-assembled monolayer (SAM) thickness, NGs with various thick-nesses of SAM is fabricated. Anisotropic wetting properties become different according to the SAM thick-ness. The NGs are used for the guidance of rat hippocampal neurons. In the last section, the combination of structural modification and chemical modification is proved to make broad range of the anisotropy. This can be observed through the combination of SNGs and SAM thick-ness control. The combined structure is also used for the guidance of the neurons. As a result, the neurons tend to be more aligned on the combined structure.