Temporal Evolutional Acoustic Pattern Generated by a 3D Printed Fresnel Lens-Focused Transducer

The controlled coupling of acoustic field has the potential to address grand scientific challenges for biological imaging, particle manipulation, therapy and intervention. However, current technologies have limited flexibility and poor control over acoustic pattern generated by a given transducer design. We report a Fresnel lens-focused ultrasonic transducer for generating excited signal dependent acoustic pressure patterns. A 3D-printed Fresnel lens is bonded to a 5 MHz ultrasonic transducer built using conventional technology. The normalized intensity maps of the acoustic pressure fields from the Fresnel lens-focused transducer under various cycle numbers of excited signal were characterized. The results demonstrated that under different cycle excitation, a temporal evolution acoustic intensity at various longitudinal locations along the focus can be generated and controlled by a 3D printed Fresnel lens focused ultrasound transducer. It suggests a simple way for acoustic pattern control which can have broad application in the future.