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Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Strain-dependent twist-stretch elasticity in chiral filaments
M Upmanyu1, H L Wang, H Y Liang
1Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP), Division of Engineering, Colorado School of Mines, Golden, CO 80401, USA. mupmanyu@mines.edu
Journal of the Royal Society, Interface
|September 27, 2007
Summary
Chirality-dependent nonlinear elasticity governs twist-stretch coupling in filamentous assemblies. Understanding these principles in DNA and carbon nanotubes can advance bio-inspired mechanical systems.
Area of Science:
- Supramolecular Chemistry
- Materials Science
- Biophysics
Background:
- Coupling between axial and torsional movements affects natural and synthetic filamentous structures.
- Chiral single-walled carbon nanotubes and B-DNA exhibit a twist-stretch coupling sign reversal at high strains.
- This shared response suggests a fundamental, chirality-dependent nonlinear elastic behavior in distinct supramolecular assemblies.
Purpose of the Study:
- To investigate the microscopic origins of nonlinearities in twist-stretch coupling.
- To establish a link between microscopic origins and effective twist-stretch coupling.
- To identify design principles governing the sign and magnitude of these couplings.
Main Methods:
- Utilized energy-based theoretical frameworks.
- Employed model simulations to analyze deformation energetics.
- Examined the interplay between energetics and coupling sign.
Main Results:
- Revealed a sensitive interplay between deformation energetics and the sign of twist-stretch coupling.
- Identified robust design principles that dictate the sign and extent of couplings.
- Demonstrated that these principles are utilized in natural systems for dynamic coupling engineering.
Conclusions:
- Chirality-dependent nonlinear elasticity is a fundamental behavior in filamentous assemblies.
- Understanding these principles offers insights into biological and technological applications.
- Broad implications exist for mechanically coupled actuation, propulsion, and transport.
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