激光空化气泡溃灭对SAP弹性小球的作用

Effect of laser-induced cavitation bubble collapse on SAP elastic ball

空化气泡溃灭时对附近弹性小球的作用研究具有重要的学术价值和实际意义。采用实验方法研究了超吸水聚合物(SAP)弹性小球附近激光空化气泡的膨胀和溃灭过程,利用扩束-聚焦后的激光在去离子水中产生单个空化气泡,通过精密位移平台精确控制空化气泡发生位置,采用高速相机获取气泡膨胀和溃灭以及弹性小球的动态变形过程,进而基于弹性小球的变形,采用数值方法获得作用在弹性小球上的挤压作用力。研究发现,弹性小球附近空化气泡存在多次膨胀和溃灭现象,其中一次膨胀和溃灭持续时间最长,对弹性小球的挤压和拉扯作用最明显。在气泡膨胀阶段,弹性小球受到膨胀气泡的面挤压所用;在气泡溃灭阶段,弹性小球受到溃灭气泡的点拉扯作用。相关研究结果对于探究超声靶向微泡破坏技术中细胞膜的通透性增加机理等现象有较好的参考作用。

The dynamical evolutions of bubble collapse and the corresponding deformation characteristics of elastic ball during the collapse of a cavitaion bubble near an elastic ball is of great academic value and practical significance.Experiments were carried out to investigate the expansion and collpase process of the laser-induced cavitation bubble near a super absorbent polymer(SAP)elastic ball.The broaden and focused laser was adopted to generate a caviation bubble in the deionized water,and the location of the generated bubble was precisely adjusted using the displacement trimming platform.The high speed camera was used in the experiment to record the process of bubble expansion and collapse,and the ball deformation.According to the deformation of the elastic ball recorded,numerical simulations were carried out to obtain the pressure applied on the elastic ball.From the experimental and numerical investigations we can find that there exist multipal collapses of cavitation bubble near the elastic ball.Among these multipal collapses,the first collapse has the strongest effect on the nearby elastic ball and lasts for the longest time.During the expansion stage,the elastic ball is squeezed.While during the collapse stage,the elastic wall is pulled.These results can promote the exploration of the mechanism of increased cell membrane permeability in ultrasound targeted microbubble destruction technology.