Interfaces between two substances (e.g., gas / liquid, liquid / liquid) are ubiquitous in nature and industry. In this project, we study two important aspects of interface: interface driven dynamics and assembly. In the area of interface driven dynamics, we conduct experiments to study how interfacial capillarity drives flow of wax inside paper under controlled temperature and pressure. The findings lead to the ability to manufacture high-resolution paper-based microfluidic devices. In the area of interface driven assembly, we study how to tune interfacial electrostatic potential and how this potential can enhance or suppress colloidal particle assembly to the interface. We conduct experiments to systematically study effects of electrolytes on particle adsorption and desorption from the interface. We also demonstrate pragmatic approaches to make Pickering emulsions through enhanced adsorption of anionic, hydrophilic colloidal particles by tuning the electrostatic potential at the interface. This has potential to broaden the range of materials that can be used to iii create solid-stabilized (Pickering) emulsions and to create new materials with complex jammed structure.