The need and the tremendous value of “very small” machines and devices were realized in late 1980’s. In the following decade, the indispensable utility of micro- or even nano-level transport phenomena in these machines was recognized, leading to the start of research and development in microflows. Researchers started investigating from a point where they deemed relevant body of knowledge on macroflows stood. Over the ensuing years, there has been significant amount of resource investment to, for example, the understanding of how the underlying physics differed as compared to macroflows and, just as importantly, what existing transport phenomena tools would be applicable. It was quickly observed that what significantly changed were the relative effects of, for example, very low Reynolds numbers, the domination of surface and interface tension, and even the continuum assumption. Much happened since then, hence, today we enjoy the ever ubiquities micro- and nano-fluidic devices this body of research and development have produced.

The author took interest in this field in the early 2000’s. This presentation will briefly sample a few of our earlier studies which varied from “design optimization of a micro synthetic jet actuator to control microflow separation,” to “electrodiffusiophoretic motion of charged spherical particle in a nanopore.” The emphasis, however, will be on our current research on two biomedical devices, using in silico approach and collaborating with adjoining experimentations: (i) a convective polymerase chain reactor (cPCR); (ii) microfluidics-aided collagen fiber (MCF) fabrication. Our goal in the first project is to develop a methodology for a portable and affordable c-PCR design intended for point-of-care use. Computational fluid and heat transfer models are developed to simulate the prerequisite convective transport fields. The search space for optimality is determined based on a specified range of the selected design variables. The convection-diffusion equations are then recast to determine and minimize the time-to-double the reagent (in our case, the double-stranded DNA) by the candidate design. For the MCF device, we are developing a new microfluidic methodology to fabricate advanced telocollagen fibers. The ultimate goal is to obtain an advanced microfluidic-based telocollagen manufacturing technology suitable to produce ligament and tendon repair and replacement grafts. Our specific goal is to provide the in silico guidance to the fabrication of collagen fibrils, which are much finer and better axially aligned, since prior research has shown that the mechanical strength of such fibers would be more favorable in achieving their purpose.