Grant Nicholas, Geiss Brian, Field Stuart, Demann August, Chen Thomas W
Department of Electrical & Computer Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
Micromachines (Basel). 2021 Sep 1;12(9):1065. doi: 10.3390/mi12091065.
Microfluidics offer many advantages to Point of Care (POC) devices through lower reagent use and smaller size. Additionally, POC devices offer the unique potential to conduct tests outside of the laboratory. In particular, Electro-wetting on Dielectric (EWOD) microfluidics has been shown to be an effective way to move and mix liquids enabling many PoC devices. However, much of the research surrounding these microfluidic systems are focused on a single aspect of the system capability, such as droplet control or a specific new application at the device level using the EWOD technology. Often in these experiments the supporting systems required for operation are bench top equipment such as function generators, power supplies, and personal computers. Although various aspects of how an EWOD device is capable of moving and mixing droplets have been demonstrated at various levels, a complete self-contained and portable lab-on-a-chip system based on the EWOD technology has not been well demonstrated. For instance, EWOD systems tend to use high voltage alternating current (AC) signals to actuate electrodes, but little consideration is given to circuitry size or power consumption of such components to make the entire system portable. This paper demonstrates the feasibility of integrating all supporting hardware and software to correctly operate an EWOD device in a completely self-contained and battery-powered handheld unit. We present results that demonstrate a complete sample preparation flow for deoxyribonucleic acid (DNA) extraction and isolation. The device was designed to be a field deployable, hand-held platform capable of performing many other sample preparation tasks automatically. Liquids are transported using EWOD and controlled via a programmable microprocessor. The programmable nature of the device allows it to be configured for a variety of tests for different applications. Many considerations were given towards power consumption, size, and system complexity which make it ideal for use in a mobile environment. The results presented in this paper show a promising step forward to the portable capability of microfluidic devices based on the EWOD technology.
微流控技术通过减少试剂用量和缩小尺寸，为即时检测（POC）设备带来了诸多优势。此外，POC设备具有在实验室外进行检测的独特潜力。特别是，介电电泳（EWOD）微流控技术已被证明是移动和混合液体的有效方法，可用于许多POC设备。然而，围绕这些微流控系统的许多研究都集中在系统能力的单个方面，例如液滴控制或使用EWOD技术在设备层面的特定新应用。在这些实验中，操作所需的支持系统通常是台式设备，如函数发生器、电源和个人计算机。尽管EWOD设备在不同层面上已展示了其移动和混合液滴的各种能力，但基于EWOD技术的完整、独立且便携的芯片实验室系统尚未得到充分展示。例如，EWOD系统倾向于使用高压交流电（AC）信号来驱动电极，但很少考虑此类组件的电路尺寸或功耗，以使整个系统便于携带。本文展示了将所有支持硬件和软件集成到一个完全独立且由电池供电的手持设备中，以正确操作EWOD设备的可行性。我们展示了用于脱氧核糖核酸（DNA）提取和分离的完整样品制备流程的结果。该设备被设计为一个可现场部署的手持平台，能够自动执行许多其他样品制备任务。液体通过EWOD进行传输，并通过可编程微处理器进行控制。该设备的可编程特性使其能够针对不同应用配置进行各种测试。在功耗、尺寸和系统复杂性方面进行了诸多考量，这使其非常适合在移动环境中使用。本文给出的结果表明，基于EWOD技术的微流控设备在便携性方面向前迈出了充满希望的一步。
