Polarizable soft interfaces such as biological cell membranes undergo significant deformations in the presence of an externally applied field due to their complex interactions with their environment. These interactions are crucial for the development of microfluidic and lab-on-chip devices, as well as other biomedical and bioanalytical systems, such as scanning ion conductance microscopy (SICM) and patch-clamping. Such interactions are also critical for electroporation-based drug delivery technologies, because the ability to precisely deliver biomolecules into target cells depends strongly on understanding the interactions between a cell membrane and applied field. However, unraveling the physics of a cell membrane in the presence of an applied field is challenging. This project will develop a systematic platform that will enable the examination of multiple physical effects relevant to polarizable soft interfaces with applied voltages. The research team will conduct mathematical, computational, and experimental studies to uncover nonlinear electrokinetic and hydrodynamic interactions of the polarizable soft interface. The effects of these interactions on nanopores at the interface will also be investigated for the precise delivery of target biomolecules into single cells. The project will provide new knowledge in cell biology and and immunology, as well as new insights into the initial molecular events associated with neurodegenerative and heart disease. The project will involve undergraduate and graduate students, and the team will conduct extensive outreach activities aimed at stimulating interest in science and engineering among students at all academic levels .
This project combines mathematical and computational approaches with an innovative experimental platform to determine the nonlinear electrokinetic effects on a polarizable soft membrane containing nanopores. It will integrate induced-charge electro-osmosis (ICEO) for the nonlinear electrokinetic phenomenon and electro-hydrodynamics for interfacial and fluid dynamics to characterize the relationship between membrane properties and nonlinear electrokinetics. At the membrane scale, the role of ICEO in determining the topographical shape of the membrane surface will be analyzed quantitatively, and the bending rigidity or stiffness of the cell membrane will then be obtained. At the pore scale, the effects of ICEO on hydrodynamic flows across nanopores on the membrane will be addressed, and the relationship between a hydrodynamic force and membrane deformation will be obtained. In parallel, microfluidic experiments using an innovative nanocapillary system will be performed at both scales for various single cells to validate the underlying models and assumptions. Armed with a quantitative model and innovative experimental system, it will be possible to add new layers to a SICM imaging process by creating a map of surface properties such as its charge and rigidity, and more importantly provide details on the way in which these properties influence the flow on the cell membrane. This project is jointly funded by the Particulate and Multiphase Processes Program and the Established Program to Stimulate Competitive Research (EPSCoR).
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
