Echo‐vision: A Dual‐Function Ultrasonic Platform for Acoustic Energy Harvesting and Varifocal Echo Imaging

ABSTRACT Ultrasonic technologies enable imaging, detection, and communication across biomedical and underwater applications, yet rigid architectures with fixed focusing often limit multifunctional integration and depth‐of‐field control. Conventional systems typically trade off aperture, coverage, and resolution, without considering unified power capture and imaging. Here, we present the prototype of Echo‐vision, a bio‐inspired ultrasonic platform that unifies acoustic energy harvesting and varifocal imaging in a single mechanically reconfigurable design. Mimicking ocular mechanisms, Echo‐vision combines an active device, a stretchable meta‐lens, and a mechanically actuated iris to realize controllable wavefront engineering and bidirectional electro‐acoustic conversion. In the energy harvesting mode, focused ultrasound charged five 1000 µF capacitors to 2.25 V at an average charging rate of 10 µC/s, providing sufficient power to drive micro‐LEDs and micro‐motors. In the echo imaging mode, radial stretching relocates the focal plane from 10 to 20 mm, enabling varifocal imaging at multiple depths. Raster‐scanned reconstructions achieve subwavelength lateral (∼0.8 λ ) and wavelength‐scale axial (1 λ ) resolution. This dual‐function integration paves the way toward self‐powered acoustic systems for underwater exploration, soft‐robotic perception, and intelligent sensing.