Stretchable 10×1-3 Composite Array for 3D Imaging on Complex Surfaces

This stretchable ultrasonic array conforms to nonplanar surfaces where rigid probes fail to maintain acoustic coupling. The device integrates a 10×10 array of 1–3 piezoelectric composites in an island-bridge architecture with five-layer serpentine copper interconnects, encapsulated in silicone elastomer. Biaxial stretchability exceeds 50%, enabling conformal contact with concave, convex, and sinusoidal surfaces. Each of the 100 elements is individually addressable. The 1–3 composites suppress lateral vibrations, yielding high electromechanical coupling (keff ~0.60), broad bandwidth (~47%), and exceptionally low crosstalk (~−70 dB). 3D volumetric imaging of internal defects through complex surfaces is demonstrated.

Parameter	Value
Array Configuration	10 × 10 (100 elements)
Center Frequency	~3.5 MHz
Bandwidth (‑6 dB)	47.1%
Piezoelectric Material	1–3 PZT/epoxy composite
Element Footprint	1.2 × 1.2 mm
Element Pitch	2.0 mm
Electromechanical Coupling (keff)	0.60
Crosstalk (adjacent elements)	~‑70 dB
Signal‑to‑Noise Ratio	~20.2 dB
Axial Resolution (FWHM)	~610 μm
Backing Material	Ag‑epoxy composite
Interconnect Geometry	Horseshoe serpentine, five‑layer
Encapsulation	Ecoflex 0030 silicone
Maximum Biaxial Stretchability	>50%
Imaging Algorithm	DMAS
Demonstrated Surface Geometries	Flat, concave, convex, sinusoidal