Light and sound waves provide the basis for energy and signal transport, and are fundamental to some of our most basic technologies, from mobile phones to motors. However, scientists have not yet developed a method that allows them to store a wave unscathed indefinitely and then direct it to a desired location when needed. Such a development would greatly facilitate the manipulation of waves for a variety of desired applications, including power generation, quantum computing, structural integrity monitoring, information storage, and more.
In a newly published article in Science Advances a group of researchers led Andrea Alù, founding director of the Photonics Initiative at the Graduate Center's Advanced Science Research Center (ASRC), CUNY, and Massimo Ruzzene, a professor of Aeronautical engineering at Georgia Tech has experimentally demonstrated that it is possible to efficiently capture and store an intact wave and then direct it to a specific location.
"Our experiment shows that unconventional excitation forms open up new possibilities to gain control over wave propagation and scattering," said Alù. "By carefully adjusting the time-dependence of the excitation, it is possible to cause the wave to be efficiently stored in a cavity and then release it in the desired direction as needed."
To prove their theory, the researchers had to adjust the temporal evolution of the waves to come into contact with non-waves-absorbing materials that would not be reflected, scattered or transmitted. This would prevent the wave impinging on the structure from leaking, and it would be efficiently trapped inside as if it were being absorbed. The stored wave could then be released when needed.
During their experiment, the researchers spread two mechanical waves in opposite directions along a waveguide rod of carbon steel containing a cavity. The time variations of each wave have been carefully controlled to ensure that the cavity retains all of the incident energy. By then stopping the excitement, or detuning one of the waves, they managed to control the release of stored energy and steer it in a desired direction as needed.
"While conducting our proof of concept experiment with Elastic Our findings also apply to radio waves and light and offer exciting perspectives for efficient energy production, wireless energy transfer, low-energy photonics, and generally improved wave propagation control," said Ruzzene.
& # 39; meta-Mirror & # 39; reflects sound waves in every direction
"Coherent Virtual Absorption of Elastodynamic Waves" Science Advances (2019). DOI: 10.1126 / sciadv.aaw3255, https://advances.sciencemag.org/content/5/8/eaaw3255
Breakthrough enables storage and release of mechanical waves without loss of energy (2019, 30th August)
retrieved on August 31, 2019
This document is subject to copyright. Apart from any fair dealings for the purposes of private study or research, no
Part may be reproduced without written permission. The content is provided for informational purposes only.