Collective Fluid Regulation Using Enzymes

Restricted (Penn State Only)
- Author:
- Song, Jiaqi
- Graduate Program:
- Chemistry
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 14, 2024
- Committee Members:
- Christine Keating, Major Field Member
Igor Aronson, Outside Unit & Field Member
Lauren Zarzar, Major Field Member
Ayusman Sen, Chair & Dissertation Advisor
John Asbury, Professor in Charge/Director of Graduate Studies - Keywords:
- Enzymatic Catalysis
Micro-pump
Liposome
Convection
Solutal Buoyancy
Collective Behavior - Abstract:
- This thesis explores the multifaceted roles of enzymes beyond their traditional function as bio-catalysts, focusing on their capability to generate chemo-mechanical force and induce movement through substrate-concentration-dependent enhanced diffusion. This novel mechano-biological aspect is examined through enzyme-powered systems across various scales, including centimeter-scale self-propelling sheets, micro-scale multi-enzyme pumps, and nano-scale enzyme-tagged liposomes. Chapter 2 investigates the scaling-up of enzyme micro-pumps, traditionally studied in microfluidic applications, to macro-scale systems. By immobilizing enzymes on large elastic sheets, this study demonstrates the creation of amplified convective flows, leading to the autonomous movement of the sheets. Factors influencing the propulsion, such as enzyme coating asymmetry and substrate concentration, are analyzed, providing insights into the application of enzyme-driven macro-robots in fluidic devices and soft robotics. In Chapter 3, the thesis delves into the behavior of multi-enzyme pump systems. By localizing multiple enzyme patches on a polymer surface, the research reveals how these pumps can autonomously direct fluid flow based on the enzyme/substrate combination present. This system demonstrates potential as a biosensor, capable of detecting specific substrates through the generated fluidic patterns. The interaction between pumps and the resultant fluid dynamics offer a novel approach to self-assembling micro-scale objects and precise fluid manipulation in microfluidics. Chapter 4 focuses on chemo-mechanical communication between artificial cells, using enzyme-tagged liposomes. By employing enzyme cascades, the study explores how chemical signals can influence the motion of liposomes, mimicking natural cellular communication. The diffusion-phoresis of enzyme-powered liposomes provides a model for understanding signal transduction and movement in synthetic cells. Through these investigations, the thesis advances the understanding of enzyme-powered systems and their potential applications in various fields, including soft robotics, bio-sensing, and synthetic biology. The findings highlight the complex interplay between enzymatic reactions, fluid dynamics, and mechanical force generation, paving the way for future research in enzyme-driven mechano-biology.