Chen, Chun WeiChaunsali, RajeshChristensen, JohanTheocharis, GeorgiosYang, Jinkyu2022-05-052022-05-052021-06-11Chen, C.-W., et al. Corner states in a second-order mechanical topological insulator. In Communications Materials, 2(1), June 2021, 6 p.2662-4443https://hdl.handle.net/10016/34701Demonstration of topological boundary modes in elastic systems has attracted a great deal of attention over the past few years due to its unique protection characteristic. Recently, second-order topological insulators have been proposed in manipulating the topologically protected localized states emerging only at corners. Here, we numerically and experimentally study corner states in a two-dimensional phononic crystal, namely a continuous elastic plate with embedded bolts in a hexagonal pattern. We create interfacial corners by adjoining trivial and non-trivial topological configurations. Due to the rich interaction between the bolts and the continuous elastic plate, we find a variety of corner states of and devoid of topological origin. Strikingly, some of the corner states are not only highly-localized but also tunable. Taking advantage of this property, we experimentally demonstrate asymmetric corner localization in a Z-shaped domain wall. This finding could create interest in exploration of tunable corner states for the use of advanced control of wave localization.6eng© The Author(s) 2021Atribución 3.0 EspañaBoltsDomain wallsElectric insulatorsTopological insulatorsCorner localizationresearch articleMaterialesFísicahttps://doi.org/10.1038/s43246-021-00170-xopen access1626Communications Materials2AR/0000030507