Shenzhen Institute of Advanced Technology Achieves Progress in Research on Temperature-Regulated Phononic Crystals

Recently, the Lauterbur Biomedical Imaging and Advanced Materials Research Team at the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, has achieved new progress in tunable phononic crystals. The related research (Phononic Crystal Tunable via Ferroelectric Phase Transition) was published in PHYSICAL REVIEW APPLIED 4, 034009 (2015). Phononic crystals—or acoustic metamaterials—

Recently, the Lauterbur Biomedical Imaging and Advanced Materials Research Team at the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, has made new progress in tunable phononic crystals. The relevant findings ( Phononic Crystal Tunable via Ferroelectric Phase Transition ) Published in PHYSICAL REVIEW APPLIED 4, 034009 (2015) 。

　　Phononic crystal ( Phononic crystal ) or metamaterials with superluminal properties ( acoustic metamaterials ) refers to composite materials composed of artificial structural units arranged in a periodic or special spatial configuration. It represents a new approach to controlling acoustic waves, following the development of natural crystals (which control electrons) and photonic crystals (which control electromagnetic waves). / Artificial composite materials for elastic waves. By designing and tuning the material composition or spatial arrangement of artificial structural units, these materials can exhibit extraordinary bandgap characteristics, allowing flexible control over the distribution and propagation of sound waves, and enabling novel applications in ultrasonic imaging. / These functional devices—such as manipulators, novel acoustic sensors, filters, acoustic superlenses, and acoustic cloaking devices—hold great promise for a wide range of applications. However, once the spatial arrangement of the basic structural units is fixed, the physical properties of phononic crystals or acoustic metamaterials become similarly fixed, which severely limits the practical applications of these artificial materials. Therefore, developing new modulation techniques is of great significance.

　　The ultrasonic technology project team at the Shenzhen Institute of Advanced Technology has innovatively proposed a material and device performance modulation technique based on temperature changes: ferroelectric phase-transition materials are used as temperature-sensitive materials in the unit structures of phononic crystals. By simply varying the ambient temperature, this phononic crystal can achieve flexible control over acoustic waves. This study represents the first-ever experimental design and fabrication of such a system. Ba _0.7 Senior _0.3 TiO ₃ (BST) Ferroelectric ceramic phononic crystal structure, at room temperature 20K Within the range of variation, the transmission frequency of sound waves has been achieved. 20% The offset. This study provides theoretical support and experimental evidence for the design of tunable acoustic metamaterials, and holds promise for developing such materials using a wider range of intelligent structures and materials—such as those sensitive to temperature, force, electricity, magnetism, and mechanical stimuli—to achieve tunable control over the properties of acoustic metamaterials. By leveraging intelligent parameters like temperature, force, electricity, magnetism, and mechanics, we can further expand the applications of these materials in advanced smart acoustic devices and biomedical ultrasound research.

　　The above research was supported by the National Natural Science Foundation of China (Key Fund, National Fund for Distinguished Young Scientists), and the Ministry of Science and Technology. 973 The project is supported by the Shenzhen Key Laboratory of Biomechanics and Technology for Micro- and Nano-Scale Applications.

　( a ) Experimental preparation Ba0.7Sr0.3TiO3 (BST) Ferroelectric ceramic phononic crystals PC ) structure, ( b ) Experimental measurement BST-PC and BST Acoustic transmission spectrum of the pure plate before and after the phase transition temperature.

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