A tunable phononic crystal system for elastic ultrasonic wave control
Yihao Song, Yanfeng Shen
Abstract
Tunable phononic crystals (PCs) are burgeoning within the engineering communities due to their adjustable capabilities for manipulating elastic waves. In this Letter, a shape memory alloy (SMA) stubbed PC is elaborated to achieve the tunable bandgaps for the control of ultrasonic waves. The tunable mechanism stems from the phase transformation of the SMA between the martensite at low temperature and the austenite at high temperature. Both numerical modeling and experimental verification are conducted to validate the achievement of the controllable stop band properties. The proposed SMA PC design could be broadened to numerous promising applications, e.g., ultrasonic wave waveguiding, flat-lens focusing, and mechanical frequency filtering, possessing enabling potential for highly adjustable wave manipulation.