IOP Publishing Acta Medica Okayama 1882-0778 18 10 2025 Multichannel topological elastic waveguide in a multilayer Kagome phononic crystal 107001 EN Yusuke Hata Department of Electrical and Electronic Engineering, Okayama University Kenji Tsuruta Department of Electrical and Electronic Engineering, Okayama University By examining the geometric characteristics of various boundaries formed within the Kagome phononic lattice and vertically stacking the lattices, we designed an elastic waveguide that enables selective propagation of topologically protected edge modes across layers in a bilayer system. This layer-selective transmission is manifested as polarized boundary modes that appear in phononic dispersions of the systems incorporating the bridge, zigzag, and armchair boundaries. We numerically demonstrated that efficient elastic layer converters and splitters can be designed, thereby paving the way for the practical development of three-dimensional elastic-wave devices. No potential conflict of interest relevant to this article was reported.