Phys.org October 10, 2019
Researchers in the Netherlands created a robotic mechanical metamaterial wherein they used local control loops to break reciprocity at the level of the interactions between the unit cells. They showed theoretically and experimentally that first-of-their-kind spatially asymmetric standing waves at all frequencies and unidirectionally amplified propagating waves emerge. These findings realize the mechanical analogue of the non-Hermitian skin effect. They significantly advance the field of active metamaterials for Hermitian physics and open avenues to channel mechanical energy in unprecedented ways. Non-reciprocal transmission of motion is potentially highly beneficial to a wide range of applications, ranging from wave guiding to shock and vibration damping and energy harvesting. Video ...read more.
Open Access TECHNICAL ARTICLE
The newly designed material. It transmits vibrations from left to right, but not from right to left. Credit: UvA/Brandenbourger et al.