Three-Dimensional Optothermal Manipulation of Light-Absorbing Particles in Phase-Change Gel Media

Area of Science:

• Materials Science
• Nanotechnology
• Optics

Background:

• Optical manipulation techniques precisely arrange colloidal particles into superstructures using lasers.
• Brownian motion in fluid media limits the stability and reconfiguration of these structures once optical energy is removed.

Purpose of the Study:

• To present a novel method for on-demand, three-dimensional (3D) optical manipulation and stable retention of colloidal particles.
• To overcome the limitations of Brownian motion in fluid media for colloidal assembly.

Main Methods:

• Utilized a phase-change solid medium composed of surfactant bilayers for colloidal particle manipulation.
• Employed optically controlled temperature-dependent interactions for microscale control of particle assembly.
• Demonstrated manipulation and retention of particles near 2D materials.

Main Results:

• Achieved stable, repeatable, and reconfigurable 3D colloidal arrangements without fluid flow interference.
• Demonstrated long-term retention of particle configurations for over 120 days.
• Showcased tunable light-matter interactions between manipulated particles and 2D materials.

Conclusions:

• The developed platform enables robust 3D optical manipulation and long-term retention of colloidal particles in a solid medium.
• This overcomes critical limitations of previous methods, paving the way for advanced applications.
• Potential applications include metamaterial fabrication, information storage, and security systems.