Dynamic manipulation of particles via transformative optofluidic waveguides.

Area of Science:

• Optofluidics and microfluidics
• Biotechnology and analytical systems

Background:

• Optofluidic particle manipulation is key for optical chromatography, biotechnology, and micro-total analysis systems.
• Current methods often rely on particle size and refractive index (n), leading to issues when optical mobilities are similar.
• Achieving size-independent manipulation based on refractive index is a significant challenge.

Purpose of the Study:

• To demonstrate rapid and dynamic particle manipulation based on refractive index (n), independent of particle size.
• To investigate the performance of integrated liquid-core/solid-cladding (LS) and liquid-core/liquid-cladding (L(2)) waveguides for optofluidic particle sorting.
• To explore how controlling the refractive index contrast between particles and working fluids affects manipulation behavior.

Main Methods:

• Fabrication of integrated liquid-core/solid-cladding (LS) and liquid-core/liquid-cladding (L(2)) waveguides.
• Experimental and theoretical characterization of the fabricated waveguides.
• Demonstration of particle manipulation based on refractive index using the developed optofluidic platforms.

Main Results:

• Successfully demonstrated rapid and dynamic particle manipulation based on refractive index (n), irrespective of particle size.
• Observed opposite manipulation behaviors for high and low refractive index particles by adjusting the contrast with working fluids.
• The LS waveguide effectively manipulated particles by refractive index.
• The L(2) waveguide offered enhanced system stability and flexibility compared to the LS waveguide.

Conclusions:

• Optofluidic platforms utilizing integrated waveguides enable precise particle manipulation based on refractive index, overcoming limitations of size-dependent methods.
• The developed LS and L(2) waveguides offer distinct advantages for particle sorting and analysis.
• These findings advance the capabilities of optofluidic systems for applications in biotechnology and micro-total analysis.