Topology optimization-guided lattice composites and their mechanical characterizations

Optimization design assisted with advanced additive manufacturing techniques opens an effective gate for us to create novel, lightweight, mechanically robust cellular materials. Among them, lattice materials with an ordered cellular architecture have been known for their high mechanical properties, low density and energy absorption capacity. Limitedly, what kinds of topologic architecture have the best performance? And how could we obtain the optimized architecture? To answer them, we here took up two challenging tasks to achieve a novel compression-resistant lattice: ① The topology optimization method was introduced to design the optimized topologic architecture. ② Metallization was used to form lattice composites to further enhance the mechanical properties of pristine polymer. The topology optimization-guided lattice with only 20% volume of solid materials quite resembles the microstructure of cuttlebone, giving an indication of a good compression-resistant ability. Furthermore, the synthesized composites exhibit high specific compressive modulus of 5417.02 MPa kg⁻¹ and energy absorption efficiency of 78%. By in situ compressive tests, digital image correlation, finite element simulation and fracture analysis, the deformation mechanism, and fracture modes were unambiguously revealed. The design strategies and findings shed light on the realization of advanced materials with tailored mechanical properties.