Hierarchical porous materials: when 3D printing meets self-assembly

Materials like bamboo, marine sponges and bone are remarkable examples of how living
organisms can synthesize hierarchical porous structures that combine mechanical efficiency, high
surface area and minimum pressure drop. By contrast, hierarchical porous materials are hard to
manufacture due to the lack of processing routes that enable deliberate control over the
material’s porous structure at multiple length scales. In this talk, I will show how 3D printing
technologies can be combined with self-assembling building blocks to fabricate hierarchical
porous materials with unprecedented mechanical efficiency and architectural control. The key
feature of our approach is to design inks with an internal structure that serves as a template for
the formation of tailored pores within the printed object. Using oil droplets, air bubbles or phase-
separating mixtures as templating structures, this methodology enables independent tuning of
porosity and pore sizes at multiple length scales. To demonstrate the potential of the process, we
3D printed complex-shaped parts with bioinspired multiscale porosity and enhanced mechanical
efficiency that cannot be achieved through state-of-the-art fabrication technologies.