정상파에 의한 입자포획 현상과 파동물리 교수-학습에의 적용

Abstract

The ultrasound is useful for trapping and manipulation of biological cells or micro-particles. Recently, several experimental results of micro-particles trapping by acoustic standing wave fields formed by plane waves have been reported. In this study, it is suggested that the standing waves by a cylindrical ultrasonic transducer can trap and aggregate the microorganism such as green algae, chlorella, and so on. Those micro-particles are trapped at specific positions determined by acoustic radiation force distribution. Thereafter, the density of the aggregation increases with the lapse time after the transducer operating. The dense colony of microorganism is easily filtered out by a glass filter. A water purification system using this method is designed and the efficiency is investigated by changing density of the microorganism after ultrasonic treatment. Consequently, it is shown that the standing waves in a cylindrical transducer can be applied to water purification.