In a groundbreaking collaboration, researchers from Pohang University of Science and Technology (POSTECH) have shattered the confines of traditional acoustic metalenses. Led by Professor Junsuk Rho from the Departments of Mechanical Engineering, Chemical Engineering, and Electrical Engineering, alongside Dr. Dongwoo Lee and PhD student Beomseok Oh, the team has unveiled the world's first wide field-of-hearing metalens. Their remarkable achievement has recently been published in the esteemed international journal, Nature Communications.

Figure 1. The Proposed Method. (Credit: POSTECH)

Figure 1 shows the proposed method. Sound waves, ubiquitous in our daily lives, emanate from vibrations in gases and liquids, playing crucial roles in fields such as medical diagnostics, telecommunications, and imaging [2]. Acoustic lenses are indispensable in harnessing the power of sound waves, particularly in focusing high-frequency ultrasound waves used extensively in medical ultrasound examinations.

Renowned for their pioneering work in metalens technology, Professor Junsuk Rho's [1] team has garnered acclaim for their innovations in both optical and acoustic metalenses. Metalenses, constructed from artificial nanostructures smaller than the wavelength of the waves, offer unparalleled control over wave manipulation while substantially reducing lens thickness. This latest research extends the concept of a "wide field-of-view" into the realm of acoustics, ushering in a new era of "wide field-of-hearing" technology with promising applications across various domains.

The wide field-of-hearing denotes the breadth of angles through which a lens can faithfully reproduce a sound image. Traditional acoustic metalenses have long grappled with sound distortion, or aberration, especially when waves approach at non-perpendicular angles [2]. However, the team has devised a revolutionary method to meticulously control the phase of the metalens, ensuring precise focusing of sound waves regardless of their angle of incidence. This breakthrough marks the first successful demonstration of a wide field-of-hearing using ultra-thin metalenses, achieving an impressive field-of-hearing of up to 140 degrees without compromising sound quality.

Professor Junsuk Rho expressed his enthusiasm, stating, "By highlighting the importance of field-of-hearing, we have introduced a new paradigm in acoustic metalens technology." He further added, "Our future endeavors will focus on exploring its applications in acoustic imaging, high-sensitivity sensing, as well as venturing into energy harvesting and underwater monitoring for submarine environments." [1]

This pioneering research was made possible through the support of POSCO N.EX.T IMPACT and a dedicated task from the Korea Research Institute of Ships & Ocean Engineering.

Source: POSTECH

References:

1. https://www.eurekalert.org/news-releases/1044535
2. https://indiaeducationdiary.in/breakthrough-metalens-extends-capabilities-from-light-to-sound/

Cite this article:

Hana M (2024), Breaking Boundaries in Sound Technology: Pioneering the Wide Field-of-Hearing Metalens, AnaTechmaz, pp. 951