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Updated: Aug 5, 2025
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Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light
Published on: September 20, 2017
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Geometry Controlled Oscillations in Liquid Crystal Polymer Films Triggered by Thermal Feedback
Divya Jayoti1,2, Akhil Reddy Peeketi1,2, Pramod Yallappa Kumbhar1,2
1Center for Soft and Biological Matter, Indian Institute of Technology Madras, Chennai 600036, India.
ACS Applied Materials & Interfaces
|March 28, 2023
Summary
Liquid crystal polymer network (LCN) films exhibit self-sustained oscillations under thermal stimulus. Temperature fluctuations and gravity drive these oscillations, enabling applications like optical choppers.
Area of Science:
- Materials Science
- Polymer Physics
- Soft Matter Physics
Background:
- Light-induced oscillations in liquid crystal polymer network (LCN) films are known.
- Oscillations in LCN films under constant thermal stimulus are recently reported, but mechanisms are unclear.
Purpose of the Study:
- Investigate the dynamics of self-sustained oscillations in LCN films under constant thermal stimulus.
- Understand the governing mechanisms and factors influencing these thermal oscillations.
Main Methods:
- Experimental studies and multiphysics finite element method (FEM) simulations.
- Developed a computational framework coupling heat transfer and mechanical deformations.
- Utilized geometrically asymmetric and symmetric LCN films with thickness tapering.
Main Results:
- Identified small temperature fluctuations (≈ 1 °C) and gravity-induced torque as drivers of oscillation.
- Achieved self-sustained oscillations in symmetric square LCN films by creating thickness tapering.
- Oscillation frequency ranged from 0.5 to 2.5 Hz, dependent on film geometry and thickness profile.
Conclusions:
- Self-sustained thermal oscillations in LCN films are driven by coupled thermal and mechanical effects.
- Film geometry, thickness tapering, and temperature fluctuations are critical factors.
- Demonstrated a thermally actuated optical chopper utilizing LCN film oscillations.
