Magnetic field-induced particle manipulation is simple and cheap as compared to other techniques (e.g., electric, acoustic, and optical) that are applicable to microfluidic devices. It is non-invasive and free of fluid heating issues that accompany nearly all other techniques, and is therefore well suited to handling bioparticles. However, traditional magnetic control requires the particles to be manipulated being magnetizable, which renders it necessary to magnetically label bioparticles. Ferrofluids have been recently demonstrated to implement nonmagnetic particle and cell manipulations in microfluidic devices with no magnetic tagging. The success of these devices relies on a comprehensive understanding of particle magnetophoresis in ferrofluid flows. Moreover, the potential of such ferrofluid-based magnetic techniques is far from being fully explored. The research objectives of this CAREER proposal are to develop a fundamental knowledge of particle magnetophoresis in ferrofluid microflows, and to explore the diverse manipulations of nonmagnetic particles in ferromicrofluidics, with the goals of establishing a new research direction in particulate and multiphase processes and developing a new technology for label-free cell handling in lab-on-a-chip applications. A comprehensive education plan will be integrated with the research goals of this CAREER proposal toward ultimately establishing a Clemson research and education program on microfluidics fundamentals and lab-on-a-chip applications. The proposed education and outreach activities include the development of a self-learner style web-based minicourses series, the development of a K-12 outreach program with an emphasis on minority students and students from families living in poverty, and the training and mentoring of graduate, undergraduate, and high school students with an active involvement of women and underrepresented minorities.
The proposed research represents the first comprehensive study of magnetophoretic transport and manipulation of nonmagnetic particles in ferrofluid microflows. It will complement the current knowledge of particle magnetophoresis in microchannels, and advance the design and control of magnetic microfluidic devices. The demonstrated label-free manipulations of nonmagnetic particles in ferrofluid microflows will find direct near-term applications in a wide range of technological solutions such as flow cytometry (via three-dimensional focusing), filtration (via trapping), biosensing (via concentration), and continuous-flow sorting (via separation). The proposed research will essentially benefit every engineering application of particle magnetophoresis in many areas such as biomedicine and environmental monitoring. It will also impact several scientific and technological communities including microfluidics, transport phenomena, polymer sciences, and bioengineering. The proposed integration of research into education will advance discovery while promoting learning through the development of research-based education materials and the training of graduate, undergraduate, and high school students in research. Practical skills gained in the laboratory and in presentations will prepare students for future careers. The dissemination of research results into the community through both archival publications and the proposed open minicourses and outreach to local high schools, especially underrepresented groups, will enhance scientific and technological understanding and benefit society.
