IEM Seminar Series: Elastodynamic metamaterials driven by broken symmetries
Event details
| Date | 26.09.2024 |
| Hour | 16:15 › 17:00 |
| Speaker | Prof. Gal Shmuel, Faculty of Mechanical Engineering, Technion, Israel |
| Location | |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract
Elastic wave manipulation is a long-lasting challenge to engineers, as numerous devices require their control. In this talk, I will present two different approaches developed in my group that share one feature: they are driven by broken symmetries.
First, I will introduce our approach for breaking Hermitian symmetry, which describes close conservative systems. Its breaking can lead to degenerate states called exceptional points, and give rise to anomalous wave propagation. The common approach to access them is by designing parity-time symmetry, which requires a challenging generation and balance of material gain and loss. I will show how the unique nature of elastodynamics can be harnessed to generate exceptional points and exotic non-Hermitian wave phenomena using nothing more than elastic layers.
In the second part, I will show how the breaking of spatial symmetry of piezoelectric media at the mesoscale generates a new material property, akin to the Willis tensor. I term it ‘the electro-momentum coupling’, since it constitutively couples the macroscopic linear momentum density and electric field. Similar to the Willis coupling, it constitutes a metamaterial knob to manipulate waves; unlike the Willis coupling, this knob is tunable by means of the electric circuit parameters.
Bio
Gal Shmuel is an associate professor at the Faculty of Mechanical Engineering, Technion, Israel. Shmuel’s group studies the mechanics and dynamics of active-, soft- and heterogeneous media. He is the 2021 prestigious ERC consolidators grant recipient for his current focus on metamaterials in elastodynamics. His recent contributions include the discovery of the electro-momentum coupling, and more generally cross-coupling of Willis type in active composites; and the realization of exceptional points and non-Hermitian phenomena in conservative elastodynamics.
Elastic wave manipulation is a long-lasting challenge to engineers, as numerous devices require their control. In this talk, I will present two different approaches developed in my group that share one feature: they are driven by broken symmetries.
First, I will introduce our approach for breaking Hermitian symmetry, which describes close conservative systems. Its breaking can lead to degenerate states called exceptional points, and give rise to anomalous wave propagation. The common approach to access them is by designing parity-time symmetry, which requires a challenging generation and balance of material gain and loss. I will show how the unique nature of elastodynamics can be harnessed to generate exceptional points and exotic non-Hermitian wave phenomena using nothing more than elastic layers.
In the second part, I will show how the breaking of spatial symmetry of piezoelectric media at the mesoscale generates a new material property, akin to the Willis tensor. I term it ‘the electro-momentum coupling’, since it constitutively couples the macroscopic linear momentum density and electric field. Similar to the Willis coupling, it constitutes a metamaterial knob to manipulate waves; unlike the Willis coupling, this knob is tunable by means of the electric circuit parameters.
Bio
Gal Shmuel is an associate professor at the Faculty of Mechanical Engineering, Technion, Israel. Shmuel’s group studies the mechanics and dynamics of active-, soft- and heterogeneous media. He is the 2021 prestigious ERC consolidators grant recipient for his current focus on metamaterials in elastodynamics. His recent contributions include the discovery of the electro-momentum coupling, and more generally cross-coupling of Willis type in active composites; and the realization of exceptional points and non-Hermitian phenomena in conservative elastodynamics.
Practical information
- General public
- Free
Organizer
- Laboratory of Wave Engineering LWE