Acoustic destruction of a microcapsule having a hard plastic shell

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 53; no. 7; pp. 1314 - 1321
• Main Authors: Koyama, Daisuke, Osaki, Atsushi, Kiyan, Wataru, Watanabe, Yoshiaki
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.07.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acoustics; Biological and medical sciences; Capsules - chemistry; Capsules - radiation effects; Charge carrier processes; Coated Materials, Biocompatible - chemistry; Coated Materials, Biocompatible - radiation effects; Computer Simulation; Destruction; Dose-Response Relationship, Radiation; Driving; Drug Delivery Systems - methods; Drugs; Exact sciences and technology; Ferroelectric materials; Frequency control; Fundamental areas of phenomenology (including applications); General equipment and techniques; Hardness; High speed; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials Testing; Medical sciences; Models, Chemical; Physics; Plastic shells; Polyvinyl Chloride - chemistry; Polyvinyl Chloride - radiation effects; Pulse duration; Radiation Dosage; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Resonant frequency; Shells; Sonication; Technology. Biomaterials. Equipments. Material. Instrumentation; Transducers; Ultrasonic imaging; Ultrasonics, quantum acoustics, and physical effects of sound; Shell; Frequency dependence; Wide band signal; Acoustic wave; Rupture; Drug dispensation; High speed cinematography; Plastics; Ultrasound
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2006.1665079

Acoustic destruction of a microcapsule having a hard plastic shell is discussed. In an ultrasonic drug delivery system, microcapsules having thin elastic shells release drugs that are contained therein when the shell is destroyed. In this paper, two subjects related to capsule destruction are discussed: the driving pulse duration for capsule destruction and the frequency dependence of capsule destruction. Optical observation of microcapsule destruction is performed with a high-speed video camera. In the case of capsule destruction by a pulse wave, the internal gas of the microcapsule cannot be ejected completely, and a portion of the internal gas remains inside the broken shell. It is found that capsule destruction by pulse waves depends on both the amplitude of the driving pressure and the pulse duration. The frequency dependence of microcapsule destruction also is investigated. In the case of capsule destruction by a low-amplitude acoustic wave, the destruction rate under the resonance condition is higher than under nonresonance conditions. By controlling the driving frequency, selective capsule destruction can be achieved.