Related Experiment Video
Updated: Jun 12, 2025
10:56
Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
12.1K
Optothermally induced active and chiral motion of colloidal structures
Rahul Chand1, Ashutosh Shukla1, Sneha Boby1
1Department of Physics, Indian Institute of Science Education and Research (IISER) Pune, Pune, 411008, India. rahul.chand@students.iiserpune.ac.in.
Soft Matter
|May 16, 2025
Summary
Researchers developed a novel method using light-activated colloids to create self-propelled microscale structures without chemicals. This optothermal approach generates active motion and chiral dynamics in artificial soft matter systems.
Area of Science:
- Soft Matter Physics
- Microscale Engineering
- Active Matter
Background:
- Artificial soft matter systems are crucial for microscale manipulation.
- Colloidal motion is typically driven by external fields or inter-colloid chemical interactions.
- Existing methods often require specific chemical environments.
Purpose of the Study:
- To investigate a novel method for generating active colloidal motion using light-induced thermal fields.
- To explore optothermal interactions for non-reciprocal colloidal dynamics.
- To understand and control microscale manipulation in non-equilibrium systems.
Main Methods:
- Utilizing a large area of optical illumination to create thermal fields.
- Employing two types of colloids: passive and thermally active (with absorbing elements).
- Simulating colloidal dynamics by solving coupled Langevin equations.
Main Results:
- Demonstrated active propulsion and chiral motion in colloidal structures.
- Optothermal interactions were shown to introduce non-reciprocity, enabling active motion.
- Localized thermal fields around active colloids drive nearby particles via thermo-osmotic forces.
Conclusions:
- This optothermal approach offers a chemical-free method for active colloidal motion.
- The study provides insights into controlling colloidal behavior in non-equilibrium systems.
- Potential applications include directed self-assembly and microfluidic manipulation.
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