A comparative review of actuation methods for Microfluidic systems

Microfluidic technologies offer advantages for a wide spectrum of applications ranging from drug discovery to water quality assessment. The contexts for the use of microfluidic systems can generally be categorized as commercial, open-source or academic research. Irrespective of the microfluidic system's objective, a form of actuation is required. This review focuses on the actuation methods available to enable the various applications. The aim is to provide an overview for the users and developers of microfluidic technologies. Therefore, off-the-shelf components or systems, and open-source projects are included. Research-based actuation methods that are supported only by research papers are excluded on the basis of accessibility. Moreover, researchers interested in the actuation systems rather than the application of microfluidic systems will benefit from the key performance indicator (KPI) framework analysis and the perspective. The KPIs (power, response time, stability, efficiency, density, cost) provide insight into pressure pumps, positive displacement actuation (syringe and peristaltic pumps), external forces (gravity pumps and human-powered systems), and microactuation. Many accessible actuation approaches are geared towards passive microfluidics. Consequently, two KPIs are prioritized: high power and stability. Other applications requiring a focus on different KPIs such as active microfluidics (response time) or point-of-care (density) have more limited accessible actuation options.