Acoustofluidic tweezers via ring resonance

Area of Science:

• Acoustofluidics
• Optical physics
• Nanotechnology

Background:

• Ring resonators (RRs) are used in sensors and optical tweezers but face challenges in microparticle manipulation.
• Limitations include insufficient force, short working distances, and photodamage with optical RR tweezers.
• Traditional acoustic transducers lack the necessary enhancement for precise microparticle control.

Purpose of the Study:

• To develop an acoustofluidic ring resonator (RR)-based tweezing method for enhanced microparticle manipulation.
• To overcome the limitations of existing optical RR tweezers.
• To improve particle trapping efficiency and control precision.

Main Methods:

• Developed an acoustofluidic method integrating acoustic waves with high Q factor (>3000) ring resonators.
• Utilized resonance interaction to enhance particle trapping forces.
• Manipulated particles by adjusting signal phase and enlarging connected waveguides.
• Strategically positioned RRs in a two-dimensional plane to strengthen the signal path.

Main Results:

• Achieved enhanced particle trapping, over 20 times greater than traditional acoustic transducers.
• Demonstrated precise manipulation of micro-sized particles within the RR by adjusting signal phase.
• Enabled rapid particle mixing by placing particles between the waveguide and RR.
• Strengthened the signal path through strategic 2D positioning of the RR.

Conclusions:

• The developed acoustofluidic RR tweezers offer a powerful new tool for microparticle manipulation.
• This method overcomes key limitations of optical tweezers, providing greater force and control.
• Has significant potential for applications in biosensing, mechanobiology, lab-on-a-chip, and cell-cell communication research.