Pentamode metamaterials approximate tailorable artificial liquids. Recently, microscopic versions of these intricate three-dimensional structures have been fabricated, but direct experimental characterization has not been possible yet. Here, using three-dimensional printing, we fabricate macroscopic polymer-based samples with many different combinations of the small connection diameter d and the lattice constant a. Direct measurements of the static shear modulus and the Young's modulus reveal that both scale approximately according to (d/a)3, in good agreement with continuum-mechanics calculations. For the smallest accessible values of d/a≈1.5%, we find derived ratios of bulk modulus B to shear modulus G of B/G≈1000.
@article{arxiv.1310.3102,
title = {Elastic measurements on macroscopic three-dimensional pentamode metamaterials},
author = {Robert Schittny and Tiemo Bückmann and Muamer Kadic and Martin Wegener},
journal= {arXiv preprint arXiv:1310.3102},
year = {2013}
}