Anisotropic, Mesoporous Microfluidic Frameworks with Scalable, Aligned Cellulose Nanofibers

Area of Science:

• Materials Science
• Biomaterials Engineering
• Microfluidics

Background:

• Cellulose paper is widely used in microfluidics due to its hydrophilicity.
• Random cellulose packing in paper requires complex microchannel designs for fluid control.

Purpose of the Study:

• To develop an anisotropic mesoporous microfluidic framework from natural wood.
• To enable pump-free microfluidic applications with enhanced mass transport.

Main Methods:

• Facile one-step delignification of natural wood to create aligned cellulose nanofibers and inherent microchannels.
• Characterization of anisotropic mass transport properties for liquids and solid particles (e.g., carbon nanotubes).

Main Results:

• The novel 'white wood' framework exhibits inherent microchannels and aligned cellulose nanofibers.
• Demonstrated fast, anisotropic mass transport (liquid and particle) with speeds ~5x greater along the channel direction.
• Fabricated chitosan films with aligned microstructures and birefringence using unidirectional capillary forces.

Conclusions:

• The anisotropic mesoporous framework ('white wood') is suitable for pump-free microfluidic chips.
• The simple preparation method offers a new pathway for developing wood-based microfluidic devices.