Multi-Material 3D Printing of Metamaterials with Targeted Frequency Response

Abstract

Metamaterials possess unconventional mechanical properties that derive from a combination of complex design and tailored material properties. While 3D printing has enabled the fabrication of complex geometries, further performance can be unlocked by multi-material fabrication of geometries with heterogeneous properties. Here, we demonstrate multi-material Digital Light Processing (DLP)-based 3D printing of neat and filled materials with viscosities differing by 3 orders of magnitude. A print method was developed to fabricate complex geometries with intricate features using highly divergent materials requiring different print parameters – including a highly filled (50 vol%) low-density syntactic foam and a neat acrylate resin – with minimal cross-contamination. A metamaterial structure is fabricated using predicted optimal parameters for a 38 kHz frequency response. The print is characterized for its dimensional fidelity and filler cross-contamination. The overall frequency response of the metamaterial structure is compared to its theoretical frequency response. This work further demonstrates its ability to fabricate functional multi-material structures using resins with a broad range of material properties.