Low-cost acoustic force trap in a microfluidic channel

Area of Science:

• Microfluidics
• Acoustic manipulation
• Biophysics

Background:

• Microfluidic devices are essential for manipulating small-scale objects.
• Acoustophoretic forces offer a label-free method for particle manipulation.
• Developing low-cost, accessible microfluidic tools is crucial for broader research adoption.

Purpose of the Study:

• To design and fabricate a low-cost microfluidic flow cell for acoustophoretic manipulation.
• To demonstrate the trapping and positional control of micro-beads.
• To establish a foundation for force spectroscopy applications on biomolecules.

Main Methods:

• Fabrication of a glass-based microfluidic cell using inexpensive, off-the-shelf components.
• Integration of a piezo actuator to generate acoustophoretic forces.
• Utilizing double-sided tape and nail polish for device leak-tightness.

Main Results:

• Successfully trapped 1.5 μm polystyrene micro-beads in a 100 μm deep channel at 7.5 MHz with 23.7 Vpp.
• Achieved precise axial positioning of trapped beads at 50 ± 0.1 μm depth.
• Measured an approximate trap stiffness of 0.6 pN/μm.

Conclusions:

• A cost-effective microfluidic device capable of acoustophoretic manipulation of micro-scale objects has been developed.
• The device allows for controlled manipulation of beads and cells, with potential applications in force spectroscopy.
• This technology can be integrated with super-resolution imaging for advanced studies of DNA mechanics and protein-DNA interactions.