Ultrasonic metamaterial at MHz frequencies using microstructured glass.

Laser-engraved glass creates a megahertz ultrasonic metamaterial with up to 20% variation in sound speed and 100× lower losses than 3D-printed alternatives.

• Why it matters: Controlling sound fields at megahertz frequencies is limited by existing metamaterial architectures that are either highly attenuating or difficult to produce, restricting their practical applications.
• What they did: The authors developed a microstructured glass metamaterial by laser engraving, defining a library of modular elements that can be combined to shape complex ultrasonic fields, supported by a theoretical model.
• The result: This metamaterial enables tailored ultrasound fields with improved control and reduced losses, advancing the potential for biomedical imaging, therapy, and nondestructive testing at MHz frequencies.