微纳气泡的三维动态表征

由于微纳气泡极易受到扰动,水溶液中微纳气泡的表征极其具有挑战性.二维成像及追踪技术可对亚微米/微米至宏观尺度级别的气泡进行无损、高速且灵活的表征和观测.然而,真实世界是三维的.受限于成像焦面的景深,二维成像技术无法完整还原气泡的空间形貌特征和局部的三维动态过程,亦无法区分气泡和其他杂质.因此,发展了一种基于数字全息显微...

Three-Dimensional Dynamic Characterization of Microbubbles

Characterizing and studying microbubbles dispersed in water remain big challenges due to their susceptible nature.2D microscopic imaging and tracking techniques are feasible to provide noninvasive,high-speed and flexible observation of bubbles in water at the level of hundreds of nanometers to macroscopic scales.However,2D imaging techniques fail to assess the morphology of micro-bubbles and capture their local dynamics in 3D,as well as to identify bubbles from impurities.Herein,a 3D tracking technique based on digital holographic microscopy(DHM)for characterizing microbubbles is developed.By combining in-line and off-axis DHM,real-time 3D trajectories,size and spatial distribution as well as phase maps of multiple microbubbles simultaneously are obtained.Refractive index of the objects can be evaluated from the phase difference with water,which is distinct for microbubbles and impurities.Therefore,DHM is expected to provide new perspective on the properties of microbubbles and may help us to have a deeper understanding about how microbubbles behave in water.