State of the Art of Low-Frequency Acoustic Modulation: Intensity Enhancement and Directional Control.
Level 5 - mechanism / opinion, no new human data
Narrative review of engineering and physical mechanisms with no new human or experimental trial data.
PubMed 40244919 · doi:10.1002/advs.202410695
What was done
This paper reviews engineering and physics methods for achieving high-intensity emission and directional control of low-frequency acoustic waves, focusing on acoustic metamaterials, source design, and wave propagation modulation techniques including acoustic resonance, focusing, and phase control.
What was found
The abstract reports no numerical data or quantitative metrics. It notes qualitatively that acoustic metamaterials enable manipulation of low-frequency acoustic waves at subwavelength scales, though current methods continue to face challenges with low energy efficiency, poor directivity, and limited controllable bandwidth.
Why it matters
Low-frequency acoustic waves suffer from severe diffraction and are difficult to focus directionally; summarizing metamaterial and source-design approaches guides the development of compact devices for medical treatment, communication, and monitoring.
Limits
The abstract provides no empirical data, quantitative comparisons, search criteria, or study counts. This is a technical narrative review rather than an experimental study or systematic review.