Understanding and optimizing laser-induced thermoelectric forces for enhanced trapping and manipulation of colloidal particles
Understanding and optimizing laser-induced thermoelectric forces for enhanced trapping and manipulation of colloidal particles
复制标题
了解和优化激光诱导热电动势以增强胶体颗粒的捕获和操纵
DOI：
10.1117/12.2567506
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Zheng, Yuebing
中科院分区：
文献类型：
--
作者：
Kollipara, Pavana Siddhartha;Lin, Linhan;Zheng, Yuebing
已经提出了几项研究来利用光诱导热梯度来控制液体溶液中的粒子轨迹。当在这些溶液中引入不同的溶质（例如盐和表面活性剂）以及微粒时，由于热场下溶液中离子的差动，会产生额外的光致热电俘获力。随着解决方案复杂性的增加，理解粒子对激光辐照度的响应变得越来越困难。更重要的是，研究颗粒热电行为的现有模型假设颗粒上具有恒定的温度梯度，但由于颗粒-溶液界面处热导率的不连续性，该模型在微观区域中已过时。为了更好地理解光致热电场下粒子的捕获和操纵行为，必须考虑温度梯度畸变。在这项工作中，提出了全尺寸有限元求解器模型来确定激光加热下微粒周围的温度变化。由此产生的温度分布用于数值评估热电场和激光诱导光热电陷阱的俘获电势。为了通过实验验证该方法，将聚苯乙烯微粒以光热电方式捕获在 CTAC 溶液中，并将实验捕获刚度与从模型获得的理论估计值进行比较。据观察，随着表面活性剂浓度的增加，捕集刚度饱和，这可以通过选择饱和开始时的最低 CTAC 浓度来优化。这里实现的模型可以很容易地扩展到任意形状的颗粒、具有不均匀表面形貌的颗粒、核壳颗粒和电解质溶液的不同组合，可以用于研究不同的现象，例如光牵引、旋转和平移。
Several studies have been proposed to control particle trajectory in liquid solutions using optically induced thermal gradient. Upon introducing different solutes such as salts and surfactants along with microparticles in these solutions, an additional optically induced thermoelectric trapping force is generated due to the differential motion of ions in the solution under thermal field. As the complexity of the solution increases, it becomes increasing difficult to understand particle response towards laser irradiance. More importantly, the existing models to study the thermoelectric behavior of the particle assumes a constant temperature gradient across the particles, which becomes obsolete in the micro-regime due to discontinuity of thermal conductivity at the particle-solution interface. For a better understanding of trapping and manipulation behavior of particles under light induced thermoelectric field, the temperature gradient distortion must be considered. In this work, full-scale finiteelement solver model has been proposed to determine the temperature variation around a microparticle under laser heating. The resultant temperature distribution is utilized to numerically evaluate the thermoelectric field and the trapping potential of the laser induced opto-thermoelectric trap. To experimentally validate this methodology, polystyrene micro-particles are trapped opto-thermoelectric-ally in CTAC solution and compared the experimental trapping stiffness to theoretical estimates obtained from the model. It is observed that trapping stiffness saturates as surfactant concentration increases which can be optimized by choosing the lowest CTAC concentration at the onset of saturation. The model implemented here can be easily extended to arbitrarily shaped particles, particles with non-uniform surface morphology, different combinations of core-shell particles and electrolyte solutions, which can be implemented to study different phenomenon such as optical pulling, rotation and translation.
影响因子：
18.3
作者：
Lin L;Hill EH;Peng X;Zheng Y
通讯作者：
Zheng Y
影响因子：
35
作者：
Lin L;Wang M;Peng X;Lissek EN;Mao Z;Scarabelli L;Adkins E;Coskun S;Unalan HE;Korgel BA;Liz-Marzán LM;Florin EL;Zheng Y
通讯作者：
Zheng Y