Material-Based Comparative Design and Simulation of Underwater Ultrasound Acoustic Metamaterial Lune-burg Lenses
پذیرفته شده برای ارائه شفاهی
کد مقاله : 1057-ISAV2025 (R1)
نویسندگان
1دانشکده مهندسی مکانیک، دانشگاه صنعتی امیرکبیر
2مرکز تحقیقات فناوری خودرو، دانشگاه صنعتی امیرکبیر
چکیده
Acoustic metamaterial Luneburg lenses are an important group of gradient refractive index acoustic lenses designed for accurate wave focusing. In recent years, researchers have explored various 2D and 3D Luneburg lens structures with unique unit cell designs. However, a lack of comparative and material driven designs of acoustic metamaterial lenses is noticeable, particularly regarding how using different materials for established unit cells affects focusing behaviour of the acoustic metamaterial lenses. Therefore, this article presents four underwater acoustic metamaterial Luneburg lenses, designed and simulated for working frequency of 40 kHz using four common 3D-printing materials: PLA, ABS, PETG and Nylon. The lenses are formed by cubic polymer unit cells with air inclusions acting as acoustic scatterers. Finite element simulations in COMSOL are performed to calculate the dispersion curves and refractive indices of the unit cells with varying filling factors. The unit cells are then arranged next to each other according to the general case of the Luneburg lens profile where the incoming waves are focused at a point on the boundary of the lens. The performance of these lenses is then evaluated by numerical simulations. The results of this study showed that the lenses made of Nylon and PLA successfully achieved the intended high intensity focal point with Nylon lens producing the highest pressure peak of 2.75 times the incident pressure amplitude and PLA lens achieving the narrowest full width at half maximum (FWHM) of 0.57λ. However, the lenses made of ABS and PETG failed to focus the incoming waves onto the predetermined focal point. The findings of this study provide a comparative understanding for designing acoustic metamaterial lenses which have a wide range of applications from industrial to medical fields.
کلیدواژه ها
Title
Material-Based Comparative Design and Simulation of Underwater Ultrasound Acoustic Metamaterial Lune-burg Lenses
Authors
Mohammad Naeim Moradi, Maryam Ghassabzadeh Saryazdi, Abdolreza Ohadi
Abstract
Acoustic metamaterial Luneburg lenses are an important group of gradient refractive index acoustic lenses designed for accurate wave focusing. In recent years, researchers have explored various 2D and 3D Luneburg lens structures with unique unit cell designs. However, a lack of comparative and material driven designs of acoustic metamaterial lenses is noticeable, particularly regarding how using different materials for established unit cells affects focusing behaviour of the acoustic metamaterial lenses. Therefore, this article presents four underwater acoustic metamaterial Luneburg lenses, designed and simulated for working frequency of 40 kHz using four common 3D-printing materials: PLA, ABS, PETG and Nylon. The lenses are formed by cubic polymer unit cells with air inclusions acting as acoustic scatterers. Finite element simulations in COMSOL are performed to calculate the dispersion curves and refractive indices of the unit cells with varying filling factors. The unit cells are then arranged next to each other according to the general case of the Luneburg lens profile where the incoming waves are focused at a point on the boundary of the lens. The performance of these lenses is then evaluated by numerical simulations. The results of this study showed that the lenses made of Nylon and PLA successfully achieved the intended high intensity focal point with Nylon lens producing the highest pressure peak of 2.75 times the incident pressure amplitude and PLA lens achieving the narrowest full width at half maximum (FWHM) of 0.57λ. However, the lenses made of ABS and PETG failed to focus the incoming waves onto the predetermined focal point. The findings of this study provide a comparative understanding for designing acoustic metamaterial lenses which have a wide range of applications from industrial to medical fields.
Keywords
Acoustic Metamaterials, Luneburg lens, Underwater Acoustics, Ultrasound