Mixing in microsystems is of importance in Lab-on -a chip devices, in microgravity processing, and in micro-heat pipes. This mixing can be caused by flow instabilities. Flow instabilities due to resonant interaction between parametric forcing and the natural frequency leads to interfacial patterns. This project is about prediction and experimental validation of the onset of interfacial patterns between fluid layers. This requires work with 3D printing of experiments, imaging, and data analysis.