Mechanical Properties of Diamond-Structured Polymer Microlattices Coated with the Silicon Nitride Film

Inspired by crystal structures of the diamond and polymer/ceramic core-shell structures of hard biological materials, diamond-structured polymer/SiN microlattices with enhanced mechanical properties have been fabricated by 3D printing and plasma enhanced chemical vapor deposition method. It is found that the compressive strength of the resultant microlattices improves with increasing silicon nitride film thickness and can reach 1.95 MPa at the thickness of 400 nm, which is 3.4 times higher than the pure polymer, but a little increase of 4.8% in density, which is only 169.2 kg m^-3. The work may provide a simplified and feasible avenue to improve the strength of low density materials.