This proposed research is targeted towards demonstrating the feasibility of constructing ultra-wideband ultrasonic transducers based on asymmetric piezoelectric structures and multiple matching layers. Transducers and arrays based on this technology would enhance medical diagnostic ultrasonic imaging by further enabling the incorporation of wideband signal processing techniques. These techniques, such as harmonic imaging, multimode operation, and chirped or coded excitation, have already begun to make large impact on the imaging industry. Initial simulations of one asymmetric structure has shown that 2 octaves of bandwidth can be achieved with high transduction efficiency. Incorporation of piezocrystal materials promises to extend the bandwidth to 3 octaves or more. This particular structure will be further simulated using 1D and 3D tools to optimize the design, develop general design rules, and evaluate the viability of currently available piezocrystal materials. Prototype transducers will be built, tested, and evaluated for viability in transducer array structures. This technology is expected to be a powerful new tool for enabling enhanced ultrasonic imaging.
If this technology is successfully demonstrated, many, if not most, commercial arrays would incorporate it into its structure. Over 70,000 new array-based probes are built every year to support the $2.5 billion medical ultrasonic imaging industry.
