Metamaterial bricks and quantization of meta-surfaces

Area of Science:

• Acoustics
• Materials Science
• Wave Physics

Background:

• Controlling acoustic fields is vital for applications like ultrasound imaging, therapy, and particle manipulation.
• Current methods often rely on fixed lenses or costly phased arrays, limiting flexibility and increasing expense.

Purpose of the Study:

• To introduce a new methodology for generating arbitrary acoustic fields using modular components.
• To demonstrate the practical application of this method in creating complex acoustic phenomena.

Main Methods:

• Development of "metamaterial bricks" that encode specific phase delays.
• Assembly of these bricks into "quantal meta-surfaces" using analogue-to-digital conversion and wavelet decomposition.
• Experimental validation of meta-surfaces for acoustic focusing, steering, and tractor beam generation.

Main Results:

• Successful experimental demonstration of acoustic focusing and steering with meta-surfaces.
• Creation of an acoustic tractor beam by stacking meta-surfaces.
• Achieved single-sided airborne acoustic levitation using meta-layers with varying quantization.

Conclusions:

• Quantal meta-surfaces offer a powerful and simplified approach to designing acoustic devices.
• This methodology represents a significant advancement towards the realization of spatial sound modulators.
• The modular nature of metamaterial bricks allows for versatile and complex acoustic field generation.