(4gg) Electrochromic Voltage Imaging at Neural and Cardiac Interfaces: From Fundamentals to Applications

Recording neuronal electrical activities or action potentials has been instrumental in unraveling the mystery of the human brain and heart. An ideal voltage imaging platform would be able to perform multi-site recording of many neurons in parallel with a high sensitivity at each recording channel. Further, it should be biocompatible, non-invasive to neurons and be capable of performing long-term recording over weeks and months. Prior electrode-based recording methods such as patch clamp or multielectrode arrays are highly invasive to cells and generally inflexible to sensing electrical fields of neurons at user-selected spatial positions. On the other hand, optical recording methods provide unsurpassed levels of flexibility and parallelization by directly imaging cell membrane voltages through voltage-sensitive fluorescent molecules. However, inserting these molecules into cell membranes often requires genetic modification of the cells, which suffers from phototoxicity, limited signal-to-noise ratio (SNR) and recording duration due to photobleaching.

My work will overcome these challenges by developing a label-free optical voltage imaging platform using electrochromic materials at the neural and cardiac interface. This approach will have comparable recording fidelity to electrode-based methods but with significantly higher parallel recording throughput. Importantly, the label-free approach is non-invasive, which allows cells to be observed and studied in their native physiological states. As an engineer trained at the interface of chemical & materials science, optics and neuroscience, I am uniquely positioned to achieve this goal. My research group will pursue three directions:

• Research area 1: Label-free voltage imaging of live cells. We will develop a label-free voltage imaging platform with high sensitivity, throughput, and spatio-temporal resolution in vitro and in vivo.
• Research area 2: Electrochromic polymers (ECPs) for biological imaging. We will perform AI-guided materials design of conjugated ECPs and study their structural-property relation on the single molecule level to optimize their electrochromic response.
• Research area 3: Single molecule biophysics of neuronal-polymer interactions. We will understand how conjugated ECPs influence the growth, adhesion and signaling of neuronal networks at the single molecule level for controlled neural tissue engineering.

From biophysical fundamentals to voltage and chemical sensing applications, progress made in these three research directions will act synergically to aid the development of the state-of-the-art label-free voltage imaging platform at neural and cardiac interfaces.

Teaching Interests:

As a teacher and mentor, I consider my primary responsibility to help my students achieve critical thinking, quantitative problem solving, and communication skills in order to tackle real-word challenges faced in their career. I prioritize to help students build their own learning styles to become lifelong learners, and apply their skillsets to solve problems beyond course materials with confidence. I am passionately committed to build a diverse, inclusive and equitable classroom for ALL, and make STEM education more accessible to underrepresented and minority students. Besides, I am always ready and eager to learn innovations in pedagogy approaches to improve my own teaching.

My strong background training and research experiences in Chemical Engineering, Materials Sciences, Biophysics, and Neuroscience; together with my previous teaching experiences of 4 undergraduate and graduate-level courses in Chemical Engineering and Materials Science have prepared me to teach several relevant courses in the field of Chemical Engineering. I am particularly interested in teaching courses on transport phenomena, complex fluids, polymer science and rheology. I am also interested in developing a graduate level course at the interface of optics, functional soft materials, and biophysics.

I seriously take the responsibility of mentoring. I wish to maximize my students’ freedom to explore their own projects within our field based on their natural curiosity and enthusiasm. At the same time, I will provide personalized guidance to each one of my students such as relevant courses or trainings to complete to ensure they are on right track towards the completion of their own projects.

Research Experience:

Graduate Research: Single molecule studies of polymers and self-assembling materials: Effects of chain topology and entanglements

Advisor: Professor Charles M. Schroeder

Department of Chemical and Biomolecular Engineering, Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign

Postdoctoral Research: Label-free optical recording and modulation of neuroelectric activities using electrochromic materials

Advisor: Professor Bianxiao Cui

Department of Chemistry, Wu-Tsai Neurosciences Institute, Stanford University

Selected Publications (8 of 13, 2 in prep):

8. Y. Zhou, E. Liu, H. Mueller and B. Cui, "Optical Electrophysiology: Towards the Goal of Label-Free Voltage Imaging", JACS (2021) In revision

7. Y. Zhou, C. D. Young, M. Lee, S. Banik, D. Kong, G. B. McKenna, R. M. R. Anderson, C. E. Sing and C. M. Schroeder, "Dynamics and Rheology of Ring-Linear Blend Semidilute Solutions in Extensional Flow: Single Molecule Experiments", JOR (2021) In revision

6. F. S. Alfonso, Y. Zhou, E. Liu, A. F. McGuire, Y. Yang, H. Kantarci, D. Li, E. Copenhaver, J. B. Zuchero, H. Mueller and B. Cui, "Label-free optical detection of bioelectric potentials using electrochromic thin films", PNAS, 117, 17260 (2020)

5. Y. Zhou, K.-W. Hsiao, K. E. Regan, D. Kong, G. B. McKenna, R. M. R. Anderson and C. M. Schroeder, "Effect of molecular architecture on ring polymer dynamics in semidilute linear polymer solutions", Nature Communications, 10, 1753 (2019)

4. Y. Zhou and C. M. Schroeder, "Dynamically heterogeneous relaxation of entangled polymer chains", Physical Review Letters, 120, 267801 (2018)

3. Y. Zhou, B. Li, S. Li, H. A. M. Ardona, W. L. Wilson, J. D. Tovar and C. M. Schroeder, "Concentration-driven assembly and sol-gel transition of π-conjugated oligopeptides", ACS Central Science, 3, 986 (2017)

2. Y. Zhou and C. M. Schroeder, "Transient and average unsteady dynamics of single polymers in large-amplitude oscillatory extension", Macromolecules, 49, 8018 (2016)

1. Y. Zhou and C. M. Schroeder, "Single polymer dynamics under large amplitude oscillatory extension", Physical Review Fluids, 1, 053301 (2016)

Selected Awards:

2019, Finalist, Frank J. Padden Jr. Award (APS DPOLY)

2018, Finalist, AIChE Area 8A Excellence in Graduate Polymer Research Symposium

2018, Society of Rheology (SOR) Travel Award

2017-2018, PPG-MRL Graduate Research Fellowship

2017, Racheff Teaching Fellowship, UIUC