Micropatterned 2D Pyrolytic Carbon Microlattices Fabricated via Stereolithography

Stereolithography (SLA) 3D printing offers a capability to shape photopolymers into a variety of periodic structures (lattices) with feature sizes ranging from submicron to millimeters. Such lattices of photopolymers can serve as a scaffold for carbon nano- and microlattices, microarchitected pyrolytic carbon materials which replicate the original topology at 60-80% shrunk dimensions after pyrolysis in an inert atmosphere. So far carbon nano- and microlattices are three-dimensional, rigid and strong, offering favorable properties especially for structural applications. Here, we employed the same SLA 3D printing and pyrolysis to fabricate two-dimensional carbon microlattices that exploit an untapped mechanical properties of microarchitected carbon: elasticity. Prepared in the same diamond patterns with three different thicknesses (70, 100, and 150µm), 2D carbon microlattices endured cyclic bending without disintegrating the structure and degrading mechanical properties, visually indicating forces at a magnitude of few tens of millinewton. The combination of sufficient structural robustness, elastic deformability and the degree of freedom in architectures is unprecedented for bulk, monolithic pyrolytic carbon, unlike the graphene assemblies that are made of nanocarbon chemically bonded or the carbon fibers whose shape is constrained to one-dimensionality. Further provided with an electrical conductivity and biocompatibility as was made of pyrolytic carbon, this emerging class of carbon material can find applications in microrobotics, micro electromechanical systems (MEMS), medical devices and so on.