Ultrasonic transducer with high vibration amplitude and large ultrasonic field has drawn considerable attention from various industries. In the field of food dehydration, a number of high-power ultrasonic transducers with extensive radiators have been proposed and used to dry heat sensitive materials and high-quality dry products. Nevertheless the design methodology for those devices is still a troublesome process and have not been widely published. In this research, an effective design method of a new i-stepped plate ultrasonic transducer was developed by using a genetic algorithm optimization scheme and finite element analyses. Based on the optimum designs, prototypes of the transducer were fabricated by a numerical control machining process. The effect of the ultrasonic field generated by the proposed design was investigated via a drying experiment of carrots which showed a considerable reduction in the drying time compared to the traditional method
