Nanopillar templating of biopolymer hydrogels augments stiffness and strength

Abstract

In nature, structural biopolymers are highly organized to allow for the development of complex tissues within a living entity, including the human body. To match the properties found in these fibrous structural tissues, synthetic biomimetic hydrogels must have an optimal combination of stiffness, strength, and toughness; though an ideal combination remains challenging to achieve. Here, we report a general strategy to design stiff, strong, and tough hydrogels by confining biopolymers with a balance of rigid and weak domains into nanopillar topography. The confinement within nanopillars templates the fiber assembly process throughout the bulk of the film. Compared to a flat control, the application of the nanopillar topography increases the bulk stiffness ~ 160% to 20 MPa, strength ~ 350% to 36 MPa, and toughness ~ 450% to 8,500 kJ m− 3. This simple templating strategy is suitable for a vast range of hydrogels, opening up the potential applications for a diverse array of materials.