Massive and fast fabrication of pentamode devices through a multiphase honeycomb-corrugation configuration

Abstract

Pentamode material (PM) is a special fluid-like acoustic metamaterial with intrinsic broadband merits. The unit cells of PM acoustic devices were based on single-material in previous reports, whose features make the available fabrication techniques very limited and the corresponding fabrication is not economic. In this investigation, a novel PM configuration composed of multi-materials is proposed to facilitate the designing and fabrication of PM devices. The novel multiphase PM configuration contains three parts: honeycomb-corrugation latticed microstructures, mass adjusting weights and interconnecting phases. The mass adjusting weights are bond to metallic latticed structure via interconnecting materials, while metallic lattices are fabricated by stamping forming technique. Simulated Annealing algorithm integrated with numerical homogenization method is developed for optimization of PM designing. A water impedance matching multiphase PM device based on this novel configuration was designed and verified in this study, and it was revealed from both numerical simulation and experiments that the designed multiphase PM device mimicked the acoustic properties of water below 25 kHz. The results indicate that the multiphase PM configuration exhibits superior performance on many aspects such as withstanding much higher hydrostatic pressure, cutting down manufacturing cost by 90% and reducing construction period by 98% compared with conventional techniques.

Keywords

• Metamaterials
• Pentamode materials
• Numerical homogenization theory
• Dispersion curve
• Simulated Annealing algorithm