Dynamic H-Bond Networks in TPP Photoresins Enable High-Strength and Directed Fluid Control.

Area of Science:

• Materials Science
• Biomimetics
• Additive Manufacturing

Background:

• Two-photon polymerization (TPP) offers high-resolution 3D printing but struggles with material limitations.
• Mechanical robustness and hydrophilicity are crucial for advanced microfluidic applications.
• Hydrogen bonding is a known strategy to improve material strength and water affinity.

Purpose of the Study:

• To develop a novel photosensitive resin with enhanced mechanical properties and hydrophilicity for TPP.
• To investigate the role of hydrogen bonding in improving resin performance.
• To demonstrate the potential of this resin in creating functional microdevices, specifically for directed liquid transport.

Main Methods:

• Engineered a novel resin (BUM) by blending a urea-pyrimidinone monomer with bisphenol A glycerolate diacrylate.
• Characterized the mechanical properties of the BUM resin (fracture elongation, strength, toughness, modulus, hardness).
• Designed and fabricated a biomimetic pointed cone structure inspired by wheat awns using TPP and the BUM resin.

Main Results:

• The BUM resin exhibited superior mechanical strength with a fracture strength of 98.5 MPa and toughness of 10.3 MJ m⁻³.
• The resin demonstrated excellent printability across submicron to millimeter scales.
• The biomimetic cone structure achieved a reverse gravity unidirectional water transport rate of 4.17 mm s⁻¹, outperforming the control group.

Conclusions:

• The developed BUM resin, engineered with hydrogen bonds, offers a significant advancement in 3D printable materials for high-strength applications.
• Biomimetic design combined with intrinsic material properties enables novel functionalities like efficient directed liquid transport.
• This work highlights the potential of hydrogen bonding engineering resins for creating advanced, multifunctional microdevices.