Tuneable hydrophoretic separation using elastic deformation of poly(dimethylsiloxane)

Area of Science:

• Microfluidics
• Materials Science
• Biotechnology

Background:

• Elastomeric microchannels offer tunable properties for various applications.
• Hydrophoretic separation is a key technique in microfluidic devices.
• Controlling separation parameters in microchannels is crucial for precise particle sorting.

Purpose of the Study:

• To demonstrate a method for tuning elastomeric microchannels for hydrophoretic separation.
• To investigate the effect of compressive strain on microchannel geometry and separation criteria.
• To achieve tunable particle separation in poly(dimethylsiloxane) (PDMS) microchannels.

Main Methods:

• Fabrication of microchannels in poly(dimethylsiloxane) (PDMS).
• Application of uniform compressive strain using acrylic substrates and bolts.
• Characterization of channel cross-section changes via confocal microscopy and finite element method (FEM).

Main Results:

• Compressive strain significantly alters the cross-sectional geometry of elastomeric microchannels.
• The hydrophoretic ordering criterion is effectively tuned by adjusting compression.
• Achieved tunable separation of particles, reducing the separation criterion from 7 to 2.5 micrometers in particle diameter.

Conclusions:

• Compressive strain is a viable method for tuning elastomeric microchannels for hydrophoretic separation.
• This technique allows for precise control over particle separation in microfluidic devices.
• The demonstrated method has potential applications in particle sorting and analysis.