| This dissertation details the design, development and characterization of a novel cellular manipulation, sorting, and transport platform based on ferrohydrodynamics. In this study, we demonstrate high performance manipulation and separation of nonmagnetic particles and live cells in ferro-microfluidic devices with 98% particle purity and 100% separation efficiency. This approach has the advantage that particle manipulation does not rely on labeling or surface modification, significantly reducing operation time and cost compared to existing techniques.;We use a combination of computer modeling and MEMS fabrication techniques, to develop an integrated microfluidic device that employs ferrofluids -- an aqueous suspension of magnetic nanoparticles -- for manipulation and separation of target particles. Conceptually, the magnetic nanoparticles in the ferrofluid direct the nonmagnetic moieties to collection sites once subjected to traveling magnetic fields. We present a detailed treatment of the physical mechanism underlying the manipulation of nonmagnetic particles using ferrofluids, including a thorough theoretical analysis of the dynamic behavior of particles within ferro-microfluidc devices.;The results presented in this Thesis reveal the potential of ferro-microfluidics in diagnostics and detection of bioassays through rapid separation and transport of target cells to detection and collection sites. Along these lines, we have employed biocompatible ferrofluids to demonstrate high efficiency separation of E. coli bacteria and sickle cells from red blood cells. Ferro-microfluidic devices presented here open new avenues in the development of next-generation point-of-care diagnostic and treatment technologies available for routine testing. |
