Dissertations, Theses, and Capstone Projects
Date of Degree
9-2022
Document Type
Dissertation
Degree Name
Ph.D.
Program
Physics
Advisor
Xi Chen
Committee Members
Steven Greenbaum
M. Lane Gilchrist
Nicolas Giovambattista
Tong Wang
Subject Categories
Biological and Chemical Physics | Engineering Physics
Keywords
Peptidoglycan, Water-responsive materials, Evaporation energy harvesting, Nano-confined water
Abstract
Water-responsive materials that reversibly deform in response to humidity changes show great potential for developing muscle-like actuators for miniature and biomimetic robotics. This thesis demonstrates that peptidoglycan exhibits ultrahigh water-responsive actuation energy and power densities, which are orders of magnitude higher than those of frequently used actuators, such as piezoelectric actuators and dielectric elastomers. Surprisingly, peptidoglycan exhibits an energy conversion efficiency of ~66.8%, which could be attributed to its super-viscous nanoconfined water that efficiently translates water’s movement to peptidoglycan’s mechanical deformation. The systematic water-responsive characterizations of peptidoglycan from different microorganisms and peptide crystals indicate that enhanced H-bonding interactions in water-responsive materials are critical to the efficient energy conversion from chemical potential of water to materials’ mechanical motions, suggesting guidelines for designing water-responsive materials with higher performance. Using peptidoglycan, we developed water-responsive composite actuators that can be integrated into a range of engineering structures, including a robotic gripper and linear actuators, which illustrate the possibilities of using peptidoglycan as building blocks for high-efficiency water-responsive actuators.
Recommended Citation
Wang, Haozhen, "High Water-Responsiveness of Peptidoglycan and its Water-Responsive Mechanism" (2022). CUNY Academic Works.
https://academicworks.cuny.edu/gc_etds/4917