Artificial materials and ultrasound to detect defects in large structures

Institute of Technology Madras and the University of Nairobi have used metamaterials to improve detection of defects in large structures by guided wave ultrasound.
Metamaterials are artificially crafted materials with unique internal microstructures that give them properties not found in nature.
Potential applications of metamaterials are diverse and include optical filters, medical devices, remote aerospace applications and among others.
Guided wave testing (GWT)
Sound waves are sent along the length of the structure rather than into the structure, allowing the waves to travel longer distances.
GWT has poorer resolution than conventional ultrasound-based testing due to diffraction limitations.