Hypothermal opto-thermophoretic tweezers.

Area of Science:

• Biotechnology and Materials Science
• Optical manipulation and Nanotechnology

Background:

• Traditional optical tweezers require high laser power and refractive index contrast, risking damage to biological samples.
• Optothermal tweezers use opto-thermophoresis but involve intense laser heating and strict solution requirements, limiting biological applications.
• Existing methods face challenges with sample damage and environmental constraints for widespread biological use.

Purpose of the Study:

• To introduce hypothermal opto-thermophoretic tweezers (HOTTs) for low-power, non-invasive trapping of diverse colloids and biological cells.
• To enhance thermophoretic trapping forces and minimize thermal damage using environmental cooling strategies.
• To demonstrate the 3D manipulation of functional plasmonic vesicles for controlled cargo delivery.

Main Methods:

• Development and application of hypothermal opto-thermophoretic tweezers (HOTTs).
• Utilizing an environmental cooling strategy to operate at sub-ambient temperatures.
• Employing opto-thermophoresis for particle and cell manipulation in native fluids.

Main Results:

• Achieved low-power, non-invasive trapping of various colloids and biological cells in their native environments.
• Demonstrated enhanced thermophoretic trapping forces at sub-ambient temperatures.
• Successfully performed 3D manipulation of functional plasmonic vesicles for cargo delivery applications.

Conclusions:

• HOTTs offer a versatile and non-invasive tool for manipulating diverse micro- and nano-scale objects.
• The environmental cooling strategy effectively enhances trapping and suppresses thermal damage.
• HOTTs show significant promise for fundamental research and practical applications in materials science and biotechnology.