Lightweight, ultra-tough, 3D-architected hybrid carbon microlattices

A lightweight material with simultaneous high strength and ductility can be dubbed the Holy Grailof structural materials, but these properties are generally mutually exclusive. Thus far, pyrolytic car-bon micro/nanolattices are a premium solution for ultra-high strength at low densities, but intrinsic brittleness and low toughness limits their structural applications. Here, we break the perception of pyrolyzed materials by demonstrating a low-cost, facile pyrolysis process, i.e., partial carbonization, to drastically enhance both the strength and ductility of a three-dimensional (3D)-printed brittle photopolymer microlattice simultaneously, resulting in ultra-high specific energy absorption of up to 60 J g-1 (>100 times higher than the original) without fracture at strains above 50%. Further-more, the partially carbonized microlattice shows improved biocompatibility over its pure polymer counterpart, potentially un-locking its biomedical and multifunctional applications. This method would allow a new class of hybrid carbon mechanical metamaterials with lightweight, high toughness, and virtually any geometry.

Automated summary

A low-cost and facile pyrolysis process called partial carbonization is used to enhance the strength and ductility of a 3D-printed brittle photopolymer microlattice. This method increases the specific energy absorption and improves biocompatibility, making it suitable for various applications including biomedical. The study proposes the possibility of creating hybrid carbon mechanical metamaterials with lightweight, high toughness, and versatile geometries.