Graded phononic metamaterials based on scalable microfabrication and design

Area of Science:

• Materials Science
• Acoustics
• Solid Mechanics

Background:

• Metamaterials offer unique wave manipulation properties.
• Phononic metamaterials focus on mechanical waves.
• Scalability is a major challenge in phononic metamaterial development.

Purpose of the Study:

• To develop a scalable framework for designing and fabricating phononic metamaterials.
• To enable the creation of complex elastic waveguides with a large number of unit cells.
• To demonstrate broadband elastic wave guiding using the developed methods.

Main Methods:

• Developed a scalable inverse design framework for spatially graded phononic metamaterials.
• Utilized a ray tracing model for wave propagation in graded beam lattices.
• Employed photolithography and etching for microfabrication of silicon-based metamaterials.
• Experimental validation using laser excitation and interferometric measurements.

Main Results:

• Successfully designed and fabricated phononic metamaterials with hundreds of thousands of unit cells.
• Demonstrated broadband elastic wave guiding capabilities.
• Framework is extendable to millions of unit cells without protocol changes.

Conclusions:

• The presented scalable design and fabrication framework overcomes limitations in phononic metamaterial development.
• This approach holds significant promise for on-chip elastic wave manipulation and integrated phononic devices.