Chen Zhihan, Kollipara Pavana Siddhartha, Ding Hongru, Pughazhendi Agatian, Zheng Yuebing
Langmuir. 2021 Feb 2;37(4):1315-1336. doi: 10.1021/acs.langmuir.0c03182. Epub 2021 Jan 7.
Liquid thermoelectricity describes the redistribution of ions in an electrolytic solution under the influence of temperature gradients, which leads to the formation of electric fields. The thermoelectric field is effective in driving the thermophoretic migration of charged colloidal particles for versatile manipulation. However, traditional macroscopic thermoelectric fields are not suitable for particle manipulations at high spatial resolution. Inspired by optical tweezers and relevant optical manipulation techniques, we employ laser interaction with light-absorbing nanostructures to achieve subtle heat management on the micro- and nanoscales. The resulting thermoelectric fields are exploited to develop new optical technologies, leading to a research field known as liquid optothermoelectrics. This Invited Feature Article highlights our recent works on advancing fundamentals, technologies, and applications of optothermoelectrics in colloidal solutions. The effects of light irradiation, substrates, electrolytes, and particles on the optothermoelectric manipulations of colloidal particles along with their theoretical limitations are discussed in detail. Our optothermoelectric technologies with the versatile capabilities of trapping, manipulating, and pulling colloidal particles at low optical power are finding applications in microswimmers and nanoscience. With its intricate interfacial processes and tremendous technological promise, optothermoelectrics in colloidal solutions will remain relevant for the foreseeable future.
液体热电效应描述了在温度梯度影响下，电解质溶液中离子的重新分布，这会导致电场的形成。热电场在驱动带电胶体粒子的热泳迁移以实现多种操控方面具有有效性。然而，传统的宏观热电场并不适合进行高空间分辨率的粒子操控。受光镊及相关光学操控技术的启发，我们利用激光与吸光纳米结构的相互作用，在微米和纳米尺度上实现微妙的热管理。由此产生的热电场被用于开发新的光学技术，从而形成了一个被称为液体光热电学的研究领域。这篇特邀专题文章重点介绍了我们近期在推进光热电学在胶体溶液中的基础理论、技术及应用方面所开展的工作。详细讨论了光照射、基底、电解质和粒子对胶体粒子光热电操控的影响及其理论局限性。我们的光热电技术具备在低光功率下捕获、操控和拉动胶体粒子的多种能力，正在微泳器和纳米科学领域得到应用。由于其复杂的界面过程和巨大的技术潜力，胶体溶液中的光热电学在可预见的未来仍将具有重要意义。
