(2jt) Fundamentals of Active Transport Phenomena in Disordered Materials.

Fundamentals of Active Transport Phenomena in Disordered Materials

Most systems related to biomedical and environmental applications are prominently disordered and active at the same time: they are populated with defects, pores and interfaces that dictate their properties, while also influenced profoundly by the activity — the ability to convert internal energy into mechanical motion and work — of living organisms such as bacteria. Tortuous pore networks inside our body tissues or soil interact with the activity of microbial colonies and substantially affects their propagation and behaviors, consequential to the spread of infectious disease and environmental sustainability. The synergy between activity and disorder also provides alternative ways to control material properties. For instance, embedding swimming microbes into colloidal gels, such as cement, can promote structural disorder and enhance the mechanical ductility of the host material, preventing disastrous material failure and increasing their life cycles. It is evident that these systems are complex: pores in tissues, cement, and soil are often partially saturated and charged, resulting in non-trivial (thermo)dynamics and solid mechanics. Dynamics of microbes couples with environmental flows, chemical gradients and intercellular biochemical signals. Artificial active particles are typically propelled by chemical reactions or electromagnetic fields, etc. Hence, it remains challenging and demands interdisciplinary efforts to comprehensively understand the transport phenomena in active disordered systems.

Leveraging my research experience in statistical and active matter physics, transport phenomena in charged porous media, and microfluidics, I will use theory and computations to investigate the transport of active matter in disordered environments. I will focus on understanding (a) how living and robotic matter propagate or localize inside disordered materials and human tissues, (b)how active matter affects the self-assembly process of colloidal materials and impact their mechanical as well as optical properties, and (c) how to design bio-computing microfluidic systems. Tackling challenging problems often necessitates the development of tools and techniques. For example, I have advanced a state-of-the-art computational framework (Active Fast Stokesian Dynamics) to study hydrodynamic interactions during active transport. With both a theoretical training background and experimental experience, I seek to collaborate across disciplines and work closely with experimentalists. Insights gained from my proposed investigations may provide guidance for novel materials design and manufacturing protocols, with potential applications in adaptive and
sustainable colloidal materials, efficient water remediation technologies and safer biomedical devices.

Teaching Interests

My theoretical training background lays a solid foundation for fundamental physical concepts and analytical capability, allowing me to teach any core courses in undergraduate and graduate curriculums of chemical engineering programs. To support my research, I plan to develop a graduate course on introduction to active matter. Students will be exposed to the frontier of this fast developing field and learn to integrate knowledge from transport, mechanics, thermodynamics and statistical mechanics to study and research in an interdisciplinary topic.

I aim to create an inclusive environment for students from various backgrounds and at different levels of preparedness. In the past, I have been a teaching assistant twice for undergraduate classes, and have mentored two undergraduate and four graduate students. To better prepare myself in teaching, I have attended the teaching workshop provided by Caltech's Center for Teaching, Learning and Outreach in fall 2022. I will also be a co-instructor for a graduate course "Wave propagation" in Division of Mechanical and Civil Engineering tentatively in spring of 2024.