Related Experiment Videos
Helicoid to spiral ribbon transition
Rouzbeh Ghafouri1, Robijn Bruinsma
1Department of Physics and Astronomy, University of California, Los Angeles, California 90025, USA.
Physical Review Letters
|May 21, 2005
Summary
Chiral materials transition from helicoid to spiral ribbons via continuous buckling. This transition, governed by the Föppl-von Kármán number, involves significant thermal shape fluctuations.
Area of Science:
- Physics, Materials Science, Continuum Mechanics
Background:
- Chiral materials exhibit complex structures like helicoids and spiral ribbons.
- Understanding the transitions between these structures is crucial for material design.
Purpose of the Study:
- To develop a continuum description for the transition between helicoid and spiral ribbon structures in chiral materials.
- To investigate the role of material properties and parameters in this structural transition.
Main Methods:
- Utilizing a continuum mechanics framework.
- Analyzing the Föppl-von Kármán number, which relates bending and stretching moduli.
- Investigating the influence of thermal fluctuations on ribbon persistence lengths.
Main Results:
- A critical Föppl-von Kármán number triggers a continuous buckling transition from helicoid to spiral ribbon.
- Two persistence lengths shorten significantly at the transition, indicating enhanced thermal fluctuations.
- The transition becomes discontinuous when ribbon width is a variable.
Conclusions:
- The study provides a theoretical framework for understanding structural transitions in chiral ribbons.
- Thermal fluctuations play a key role in the continuous buckling transition.
- Material parameter choices, like ribbon width, can alter the nature of the transition.