Ultrasound focusing enhancement through the stiff plate with inversely optimized metamaterial lens

Conventional ultrasound focusing implementations generally rely on steering the transmitted ultrasound wave through the openings in the designed lenses, which are ineffective for ultrasound focusing through a plate without openings. Here, we have proposed an inverse optimization scheme to fabricate a metamaterial lens that can enhance ultrasound focusing through a stiff plate immersed in water without any openings. This metamaterial lens can enhance the power transmission, and at the same time focus the transmitted power well. The optimized acoustic focusing enhancement lens shows great potential in medical imaging and disease treatment.