This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
This study will perform a comprehensive computational study on the role of membrane elasticity, non-axisymmetry, and particle-wall interactions on capsule dynamics. Manipulation of single cells in microfluidic devices has gained momentum in the last decade with the development of novel microdevices for in vitro fertilization, cell-culture studies, forensic analysis, and diagnosis of diseases such as cancer, diabetes, and malaria. A better understanding of the dynamics of natural cells and artificial capsules in a microfluidic device will lead to engineering of specialized biomedical microdevices. The overall research objectives of this project are to determine the effects of inertia on the three-dimensional non-axisymmetric motion of capsules in channels and of a nonuniform confining wall on capsule dynamics. The research objectives will be accomplished by developing a 3-D numerical model for the pressure-driven motion of non-nucleated cells and capsules in microchannels filled with a Newtonian liquid. The effect of the confining wall will be determined by studying flow in a rectangular channel, a sudden expansion or contraction with circular and rectangular cross-sections, and a corrugated tube with circular cross-section. A volume-of-fluid (VOF) method in conjunction with a front-tracking scheme explicitly tracks the membrane location. This numerical scheme accurately predicts the interfacial topography and stresses allowing simulations of capsules with large deformations as they squeeze through channels. The method can also easily be extended to consider multiple interacting capsules. Various constitutive equations describing the behavior of the biological cell membranes and artificial capsules will be considered. Critical conditions for the breakup of the capsules will also be identified. The ability to relate the shapes and velocities of cells in microfluidic devices to the mechanical properties of the membrane opens up exciting possibilities for the development of novel single-cell microdevices as a diagnostic tool for various diseases. In addition to advancing the field of interfacial phenomena in microfluidic devices, the results from this research will be incorporated in a new elective course on "Microfluidics: Theory and Applications" taught by the PI and an existing biomedical engineering course in the chemical engineering curriculum. The PI will also invite high school students to the lab through Project SMART to encourage students to pursue science and engineering careers. Finally, the PI will encourage the involvement of women and members of minority groups in her research and in the field of science and engineering in general.
