Thermo-magnetic-Acoustic Radiation Using Free-standing Nano-Thin Films

Thermo-acoustic radiation from thin films has been a subject of research and practical interest in recent years. However, research in the coupling of thermo-acoustics and magneto-acoustics has been very lacking. In this study, a free standing nano-thin film connected to a stable AC current generator is placed in a harmonic magnetic field to enhance the acoustic power in a multi-field thermo-magneto-acoustic generation. The coupled thermo-magneto-acoustic system shares the same acoustical unit with very few additional components. In the presence of a harmonic magnetic field, thin-film vibration is excited instead of being still in the classical thermo-acoustic system. And the oscillation perpendicular to the nano-thin film is driven by the electromagnetic force. Moreover, the thermo-acoustic and magneto-acoustic sub-system share the same emissive frequency and interact on the fluid-solid interface in a harmonic magnetic field rather than acting as two independent systems in a static magnetic one. The system response of thermo-acoustics and magneto-acoustics can be generally matched when suitable parameters are introduced. Some preliminary results show that the acoustic response of this new multi-field coupled system in a harmonic magnetic field can be significantly improved comparing to the classical system without magnetic effects.