Paper-thin multilayer microfluidic devices with integrated valves.

Area of Science:

• Microfluidics
• Biotechnology
• Optical Microscopy

Background:

• Integrated valve microfluidics enables automated nanoliter fluid delivery for high-throughput experiments.
• Traditional microfluidic devices are too thick (around 5 mm) for applications with limited sample thickness tolerance, such as 4-pi microscopy and optical tweezer applications.

Purpose of the Study:

• To develop a new generation of integrated valve microfluidic devices with significantly reduced thickness.
• To overcome the form-factor limitations of existing microfluidic devices for advanced imaging and manipulation applications.

Main Methods:

• Fabrication of ultra-thin microfluidic devices (<300 μm) using a novel soft-lithography technique.
• Demonstration of on-chip micro-valves with full functionality and reliability in the thin-chip design.
• Integration of the thin-chip with high-resolution inverted microscopy for automated fluid control during imaging.

Main Results:

• The thin-chip microfluidic devices achieved a thickness of less than 300 μm, including the substrate.
• Demonstrated improved signal-to-noise ratio for two-color stimulated Raman scattering (SRS) imaging of single cells using the thin-chip.
• Successfully performed simultaneous on-chip magnetic manipulation of beads and fluorescent imaging with the thin-chip.

Conclusions:

• The novel thin-chip microfluidic devices resolve the thickness limitations of traditional devices.
• These thin-chips offer enhanced performance for high-resolution imaging techniques like SRS microscopy.
• The technology holds potential for applications in single-cell multi-omics, including sorting and bead capture.