Acoustofluidic black holes for multifunctional in-droplet particle manipulation

Area of Science:

• Acoustics
• Fluid Dynamics
• Nanotechnology

Background:

• Acoustic black holes effectively trap acoustic waves for applications like energy harvesting and vibration control.
• The effects of acoustic black holes on micro/nanoparticles in fluids remain unexplored.
• Acoustofluidics combines acoustics and microfluidics for particle manipulation.

Purpose of the Study:

• To introduce acoustofluidic black holes (AFBHs) for manipulating micro/nanoparticles within droplets.
• To investigate the wave energy trapping and wavelength shrinking capabilities of AFBHs.
• To explore the acoustic radiation forces and streaming effects induced by trapped energy on particles.

Main Methods:

• Development of acoustofluidic black holes (AFBHs).
• Analysis of acoustic wave energy trapping and wavelength reduction.
• Investigation of acoustic radiation forces and acoustic streaming in droplets containing particles.

Main Results:

• Demonstrated versatile particle manipulation: translation, concentration, and patterning within droplets.
• Observed significant wave energy trapping and wavelength shrinking effects by AFBHs.
• Quantified acoustic radiation forces and acoustic streaming generated by the AFBHs.

Conclusions:

• AFBHs provide a novel toolset for in-droplet particle manipulation.
• This work bridges acoustofluidics and acoustic black hole research.
• AFBHs hold potential for applications in biosensing, point-of-care testing, and drug screening.