Optoelectrowetting for actuation of nanoliter droplets, revisited

重新审视用于纳升液滴驱动的光电润湿

• 批准号: 500403890
• 负责人: Professor Dr. Henning Fouckhardt
• 金额: --
• 依托单位: Arbeitsgruppe Integrierte Optoelektronik und Mikrooptik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2022
• 资助国家: 德国
• 起止时间: 2021-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/500403890?language=en
• 关键词: Optoelectrowetting; actuation; nanoliter; droplets; revisited

In the preliminary numerical investigations of the applicant's group, it was proven that the previously widespread assumption that droplet pushing with OEW (optoelectrowetting) is weaker and occurs at higher frequencies than droplet pulling is not generally valid. A closer look at the equations commonly used to describe EWOD (electrowetting) and OEW and appropriate modifications show different solutions for the contact angle change versus frequency when the OEW control light is turned on. The fact that droplet shifting can also be relatively strong and occur at low frequencies (e.g., around 50 Hz) was also evidenced by experiments. This diversity also makes it difficult to optimize the chips and their operation. Nevertheless, it would be helpful for potential applications of droplet actuation using OEW if both pulling and pushing were available as actuation options: pulling, e.g., to fuse droplets, pushing possibly to split droplets.Thus, in order to open up OEW for practical and feasible use, more detailed experimental and numerical investigations must be undertaken. This is what this project is intended to revolve around, without any specific application in the background.Both the applied voltage and its modulation frequency have a strong and not easily predictable influence on the contact angle and the net OEW force. Moreover, the electrical conductivity and the size of the droplets play a role, so that an optimization for droplets of certain properties does not automatically mean an optimization also for droplets of other parameters.Optimization of devices and operation also means finding and using the maximum of the normalized OEW force on the droplets. The light line OEW (LL-OEW) concept proposed by this group has principal advantages in this regard (not only in terms of setup geometry), because the light line allows for a larger part of the droplet's contact line to be illuminated and utilized than with perpendicular incidence of light in the usual OEW concept. The results of the project would expand the toolbox of OEW use for droplet manipulation.

在对申请人组的初步数值研究中，事实证明，先前广泛的假设是，用OEW推动液滴推动（光链球运动）较弱，并且在较高的频率下发生的液滴比液滴拉动较高。仔细观察通常用于描述EWOD（电网）和OEW和适当修改的方程式，显示了对接触角变化与频率的不同解决方案。通过实验也证明了液滴转移的事实也可能相对强，并且在低频（例如50 Hz）处发生。这种多样性也使优化芯片及其操作变得困难。然而，如果拉力和推动都可以作为驱动选项，例如拉力，例如拉力液滴，可能会推动拆分液滴。必须进行可行的使用，更详细的实验和数值研究。这就是该项目旨在围绕的目的，而没有任何特定的应用程序。此外，液滴的电导率和大小起作用，因此对某些特性液滴的优化也不意味着对其他参数的液滴的优化。设备和操作也意味着查找并使用最大液滴上的归一化OEW力。该组提出的Light Line OEW（LL-OEW）概念在这方面具有主要优点（不仅在设置几何学方面），因为光线允许液滴的接触线的更大部分被照亮和使用在通常的OEW概念中，光的垂直发生率。该项目的结果将扩展OEW使用的工具箱进行液滴操作。