(6fr) Soft Materials and Bio-Integrated Devices: From Complex Colloidal Systems to Skin/Brain-Interfaced Biosensors

My primary research interests lie in colloids, interfacial science, and bio-integrated electronic devices for solving grand challenges in energy-efficient separations and human healthcare. My doctoral research focused on colloids, polymer, and interfacial science. I made two major contributions to the colloid community. My first accomplishment is the discovery of a new class of soft materials called capillary foams. I studied its stabilization mechanism, the effect of system parameters, and its potential applications in energy-efficient separations. This research has been reported by many press releases, such as Science Daily, NSF News, and World Industrial Reporter. My second contribution is that I answered a question that exists in the colloid community for a few decades. Over one hundred years ago, people found that colloidal particles with suitable wettability can adsorb to (and stabilize) the fluid-fluid interfaces. However, there is a long ongoing debate about whether the adsorption of non-amphiphilic particles in the interface can change the interfacial tension. I answered this question by conducting systematic experimental and theoretical studies. My studies show that particles do reduce the interfacial tension, which depends on the packing density and contact angle of particles in the interface. This insight is important for understanding and controlling the assembly of non-amphiphilic nanoparticles at fluid–fluid interfaces, which is crucial for applications from food technology to oil recovery.

My postdoc training focuses on skin/brain-interfaced devices for human health applications. Chronic kidney disease (CKD) is a condition where kidneys are damaged and cannot filter blood as well as healthy ones. 30 million or 15% of US adults are estimated to have CKD but most of them are not aware of it at an early stage of the disease. Early detection and treatment can often keep chronic kidney diseases from getting worse. Therefore, a novel method for painless and stress-free kidney health monitoring is highly desirable. I developed a wearable sweat sensor that can capture and analyze creatinine and urea in sweat for the early detection of CKD. Another significant direction I am working on is the design and fabrication of new tools for neuroscience. Diseases related to the central and peripheral nervous systems, such as depression, anxiety, addiction, pain, Alzheimer's, and amyotrophic lateral sclerosis, affect the life quality of millions of people worldwide. To understand the function of neural networks and the causes of these mental health problems, I designed and fabricated injectable/implantable optofluidic devices for brain and peripheral nerve interfaces. This technology has been transferred from the research bench to commercialization by a startup company Neurolux (http://neurolux.org/).

Postdoctoral Advisor: Professor John A. Rogers, Northwestern University

Ph.D. Advisors: Professor Sven H. Behrens and Professor J. Carson Meredith, Georgia Tech

Teaching Interests:

My teaching philosophy is to develop a supportive environment for my students, where they can develop their interests in both fundamentals and a broader impact of a given subject. I also intend to equip my students with an effective way of learning and collaboration that they can benefit from for their lifetime. ‘Big picture’: I believe that courses that focus on both impact and core principals will better motivate students from various backgrounds, interests, and career goals. As a teacher, it is my responsibility to convey the importance of Chemical Engineering topics and my passion for them, so that students see the value and potential impact of their work. I will accomplish this by relating course materials to real-life problems. I will begin each semester by asking students why they register for my course and tailoring examples to the students’ interests. These activities can be incorporated into large classes without sacrificing effectiveness. Effective way of learning: In this rapidly changing world, the knowledge in science and engineering is expanding exponentially. Therefore, instead of solely subject-oriented teaching, it is critical to stimulate students’ curiosity to explore different fields and teach them learning skills that they can apply to various learning processes. Collaboration: Learning to work together to solve problems is a crucial skill for any engineering career. To promote this, I will present problems and probe questions pertaining to lecture concepts for students to work on and discuss together during class. Collaboration makes engineering more accessible to a broader range of students by exposing them to a range of approaches to problems and by reducing competition. While competition can help some types of students thrive, highly competitive classrooms have been shown to turn students away from engineering. As a graduate student at Georgia Tech, I experienced an environment where students worked together to solve homework problems and make sure everyone in their study group understand the material.