Manipulating particle trajectories with phase-control in surface acoustic wave microfluidics

Area of Science:

• Acoustic-microfluidic devices
• Surface acoustic wave resonators
• Particle manipulation technology

Background:

• Acoustic manipulation offers label-free particle handling.
• Integrated microfluidic systems are crucial for lab-on-a-chip applications.
• Precise control over particle trajectories is essential for separation and sorting.

Purpose of the Study:

• To develop and demonstrate a 91 MHz surface acoustic wave resonator with integrated microfluidics.
• To investigate the manipulation of particle trajectories using acoustic forces.
• To achieve precise spatial and angular control over multiple particle streams.

Main Methods:

• Fabrication of a 91 MHz surface acoustic wave resonator with integrated microfluidic channels (flow focus, expansion, binning regions).
• Manipulation of acoustic node positions by varying the electronic phase between transducers.
• Real-time tracking and analysis of 3 µm latex bead trajectories in a water-based solution at room temperature.

Main Results:

• Demonstrated pseudo-static control of acoustic node positions via transducer phase adjustment.
• Achieved simultaneous control of 9 bead streams with precise spatial control (-0.058 µm/deg ± 0.001 µm/deg).
• Showcased trajectory control of bead streams towards a selected bin with angular control (0.008 deg/deg ± 0.0002 deg/deg).

Conclusions:

• The integrated acoustic-microfluidic device effectively manipulates particle trajectories.
• Phase-controlled acoustic nodes provide a robust method for precise particle stream steering.
• This technology holds promise for advanced particle sorting and analysis in microfluidic systems.