CAREER: Jamming and Phase Transition of a Suspension of Soft Particles in Porous Media

Nontechnical Abstract

This CAREER award will investigate how soft particles flow or become trapped in porous environments such as filters, tissue, and soil. Soft particles suspended in fluids are abundant in the food industry, pharmaceuticals, blood flow, and microbial ecosystems in the natural environment. The investigators will use microscopy to quantify the flow, transport, and clogging of soft particles of prescribed sizes within porous environments fabricated using a microfluidic 3D printer.

These studies will reveal how particle elasticity and deformability, in conjunction with the structure of the porous medium, influence the transition from a flowing suspension of particles to a clogged state. The project will enhance student participation in career-building activities by integrating experimental skills and teamwork into freshman physics courses.

Additionally, it will provide opportunities for community building and improve the retention of students through collaborative projects and teamwork. Technical Abstract

This research will establish a fundamental understanding of the cooperative dynamics of deformable granular particles in porous media. It will investigate how microscale particle interactions, elasticity, and pore network connectivity influence macro-scale transport by integrating microscopic measurements and bulk permeability analysis. Two fundamental questions will be addressed: (1) How does the network of pores in a medium determine the formation of particle clusters within individual pores and enhance the long-range spatial order within clusters? (2) What is the microscopic origin of the increased apparent viscosity of a suspension of particles flowing through a porous medium at small shear stress?

By connecting particle elasticity, cluster formation, and porous medium properties, this study will identify the regimes in which either single-particle properties or collective transport dominate, leading to new insights into clogging and material transport in biological and industrial applications. Results from this project will advance the physics of phase transition in a porous structure by quantifying the spatial correlation of particles within the medium.

More broadly, this research will provide a foundation for developing models for anomalous shear thickening and jamming transitions based on the local dynamics of particles, applicable to various nonequilibrium systems confined to a rigid matrix.

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.