Tunable Acoustic Gradient Lens

Changing the gradient changes how acoustic energy is refracted as it crosses regions with different acoustic properties. A differently distributed spatial variation can therefore shift the focal position or redirect the beam. This tunability lets an operator alter where sound is concentrated without replacing the lens or mechanically repositioning the device.

Regions with differing acoustic impedance or sound velocity provide the contrast needed for refraction. As sound encounters those regions, differences in propagation conditions change the wavefront’s path. The resulting spatial gradient determines whether the beam is redirected, refocused, or shifted, making the acoustic-property distribution a central control variable.

Unlike a mechanically repositioned acoustic element, a Tunable Acoustic Gradient Lens changes its effect by modifying the spatial gradient in acoustic properties. The wavefront, focal position, or beam direction can consequently be adjusted while the device remains in place. This distinction supports reconfiguration and avoids relying on physical motion to steer acoustic energy.

In practice, tuning means altering the gradient so refraction produces a desired beam direction or focal position. The resulting wavefront behavior provides the key observable effect of the adjustment. This approach lets researchers change acoustic delivery while preserving a fixed, contact-free arrangement for a given experiment.

For ultrasound imaging, tunability can adapt the location or direction of acoustic focusing to the needs of the measurement. Because the lens can redirect wavefronts without mechanical movement, an imaging system may gain flexibility in how it delivers or concentrates sound. The result is more adaptable acoustic control for diagnostic and research-oriented imaging workflows.

Localized acoustic stimulation benefits from the ability to shift the focal position. By redirecting acoustic energy toward a different region, the lens supports adaptable stimulation experiments rather than requiring one fixed focus. Its contact-free operation also allows acoustic delivery without direct physical contact with the target.

In cell and particle manipulation, changing the gradient can alter where acoustic energy is concentrated or directed. That reconfigurability supports experiments requiring controlled positioning of acoustic influence without mechanically moving the device. The broader bioengineering value lies in combining spatial control with a noncontact format for research systems.