该文应用压电陶瓷器件激发频率1 MHz的兰姆波在非压电基板上进行了微流体温度分布的研究。经理论分析表明,兰姆波向流体中辐射纵波以及兰姆波在介质中传播时的粘性摩擦损失产生了声热效应。采用红外摄像机观察液滴从兰姆波激发直至达到稳态时的热分布变化,发现液滴在兰姆波入射一侧的温度高于其他区域且高温区域有向顶部扩散的趋势。观察不同液体黏度液滴的声热现象,发现油滴的温度扩散更均匀,动力学行为更弱。采用有限元分析声流和声热效应,发现液滴在顶部区域声流速最大,在声流作用下,液滴的高温区域扩散至顶部。

Microfluidic temperature distribution on a non-piezoelectric substrate is studied using Lamb waveswith 1 MHz excitation frequency in piezoelectric ceramics.Theoretical analysis demonstrates that the acoustothermaleffect is induced by the Lamb waves radiating longitudinal waves into the fluid and viscous friction loss.An infraredcamera observes the thermal distribution of droplets from Lamb wave excitation to a steady-state temperature.Thedroplet temperature on the Lamb wave radiation side is higher than that of other areas, and the high temperature areatends to spread to the top.Regarding the acoustothermal phenomena of droplets with different liquid viscosities,the temperature distribution of an oil droplet is more uniform and exhibits weaker dynamic behavior.Finite elementanalysis of the acoustic flow and thermal effect demonstrate that the droplet high temperature diffusion trend correspondsto the maximum acoustic flow inside the droplet.

TN712;O429

国家自然科学基金资助项目(51505274)