Poster: Amplitude dependant control of harmonic waves through topological solitons

In this work, we use analytical, numerical, and experimental methods to investigate the utility of metamaterials in controlling harmonic waves based on both amplitude and frequency. Our metamaterials are composed of free floating disks with embedded permanent magnets confined within a magnetic boundary. By programming the boundary's magnetic field, we can change the energy landscape of the metamaterials and the equilibrium positions of the disks. Both disk position and surrounding magnetic field dictate the stability of the unit cell and its transmission characteristics. By engineering the metamaterials to retain bi-stable configurations (i.e., two stable phases), we elucidate the required conditions for a transition wave ( i.e., a topological soliton) to nucleate causing a phase change within the material. Each of these phases has its own transmission frequency range. We harness this phase change to control harmonic waves based on their amplitude and frequency. We showcase different scenarios with the same metamaterial configuration that can phase change from transmission to attenuation and vice versa. Such material can be utilized as a filter to either high or low amplitude signals. In addition, we show phase transitions taking place while preserving the metamaterial's state of attenuation or transmission. Such materials can continue their functionality (i.e., either attenuation or transmission of waves) while keeping a record of extreme events that can cause their transition. Our metamaterials can open the door for the next generations of advanced and functional acoustic devices.