Digital holography as 3D tracking tool for assessing acoustophoretic particle manipulation

Area of Science:

• Microfluidics
• Acoustic Manipulation
• Digital Holography
• Particle Imaging

Background:

• Microfluidic devices enable precise control over small volumes.
• Acoustic manipulation uses sound waves to move micro-particles.
• Digital holography (DH) offers non-invasive 3D particle tracking.

Purpose of the Study:

• To integrate DH imaging with acoustic manipulation for micro-particle analysis.
• To use DH for precise 3D tracking of particles in microfluidic channels.
• To investigate particle behavior under ultrasound pressure fields.

Main Methods:

• Utilizing DH for efficient 3D tracking of multiple micro-particles.
• Measuring particle positions under stationary ultrasound pressure fields.
• Analyzing axial and transversal particle displacement to verify standing wave nodes.
• Quantifying particle aggregation dynamics using aggregation rate metrics.

Main Results:

• DH accurately determined particle positions in 3D, confirming numerical predictions of ultrasound standing wave nodes.
• Axial displacement verified node positions along the wave propagation axis.
• Transversal movement indicated the presence of nodes in the planar directions.
• DH successfully monitored sphere aggregation within trapped nodes.

Conclusions:

• The combined DH and acoustic manipulation technique provides robust 3D particle tracking in microfluidics.
• This approach allows for precise characterization of acoustic fields and particle behavior.
• The method is valuable for studying micro-particle dynamics, including aggregation.