Related Experiment Video
Updated: Feb 27, 2026
09:39
Characterizing Dissipative Elastic Metamaterials Produced by Additive Manufacturing
Published on: June 28, 2024
1.7K
Non-reciprocal wave propagation in modulated elastic metamaterials
H Nassar1, H Chen1, A N Norris2
1Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA.
Proceedings. Mathematical, Physical, and Engineering Sciences
|July 11, 2017
Summary
Time-reversal symmetry is broken in modulated metamaterials, enabling one-way elastic wave control. These materials demonstrate unidirectional wave transmission, amplification, and blocking for advanced elastic wave applications.
Area of Science:
- Physics
- Materials Science
- Acoustics
Background:
- Elastic wave propagation typically adheres to time-reversal symmetry.
- Metamaterials offer unique wave manipulation capabilities.
- Modulation of material properties can introduce novel phenomena.
Purpose of the Study:
- To investigate the breakdown of time-reversal symmetry in modulated metamaterials.
- To demonstrate and analyze one-way elastic wave phenomena.
- To explore non-standard effective mass operators and non-reciprocal behaviors.
Main Methods:
- Analytical asymptotic analysis using coupled mode theory.
- Numerical simulations in harmonic and transient regimes.
- Homogenization limit analysis for high-amplitude modulations.
Main Results:
- Demonstrated breakdown of time-reversal symmetry in resonant mass-in-mass lattices.
- Observed one-way wave transmission, conversion, amplification, and blocking.
- Recovered non-standard effective mass operators with negative values over large frequency bands.
Conclusions:
- Modulated metamaterials exhibit non-reciprocal behaviors and non-standard effective mass operators.
- These materials offer significant promise for advanced elastic wave control.
- Potential applications include one-way wave conversion and amplification.
Related Concept Videos
01:28Standing Waves in a Cavity
1.5K
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
1.5K
01:07Propagation of Waves
3.1K
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
3.1K
01:30Electromagnetic Waves in Matter
4.1K
Electromagnetic waves can travel in the vacuum as well as in matter. For example light, which is an electromagnetic wave, can travel through air, water, or glass.
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the medium, μ.
Furthermore,...
Consider the electromagnetic wave passing through a dielectric medium. In such a case, Maxwell's equations get modified. In Ampere's law, ε0 , the dielectric permittivity of free space is replaced with ε, the permittivity of dielectric. Also, the vacuum permeability μ0 is replaced by the permeability of the medium, μ.
Furthermore,...
4.1K
01:04Travelling Waves
7.2K
A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. Mechanical waves are governed by Newton's laws and require a medium to travel. A medium is a substance in which a mechanical wave propagates, and the medium produces an elastic restoring force when it is deformed.
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
7.2K
01:15Standing Electromagnetic Waves
2.4K
Electromagnetic waves can be reflected; the surface of a conductor or a dielectric can act as a reflector. As electric and magnetic fields obey the superposition principle, so do electromagnetic waves. The superposition of an incident wave and a reflected electromagnetic wave produces a standing wave analogous to the standing waves created on a stretched string.
Suppose a sheet of a perfect conductor is placed in the yz-plane, and a linearly polarized electromagnetic wave traveling in the...
Suppose a sheet of a perfect conductor is placed in the yz-plane, and a linearly polarized electromagnetic wave traveling in the...
2.4K
01:07Reflection of Waves
4.7K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
4.7K