8F-5 A Visualization Tool for High Intensity Focused Ultrasonic Field Using LEDs and Piezo-Elements

A tool for directly visualizing intense ultrasonic field is considered in this study, where a light emitting diode (LED) is connected to a piezoelectric ceramic element. As the piezoelectric element generates electric voltage in proportional to ultrasonic pressure applied to the element, the LED is turned on by the voltage. The sound pressure is directly observed as a light intensity of the LED by human naked eyes. In this report, first, we describe the principle of the sensor, then present a configuration of hydrophone based on the present method. Second, visualizations of a focused field excited by a concave transducer and a standing wave field in an ultrasonic cleaner are demonstrated using an array version of the proposed sensor.