Abstract
Droplet microfluidics (DMF) is a fluidic handling technology that enables precision control over dispensing and subsequent manipulation of droplets in the volume range of microliters to picoliters, on a micro-fabricated device. There are several different droplet actuation methods, all of which can generate external stimuli, to either actively or passively control the shape and positioning of fluidic droplets over patterned substrates. In this review article, we focus on the operation and utility of electro-actuation-based DMF devices, which utilize one or more micro-/nano-patterned substrates to facilitate electric field-based handling of chemical and/or biological samples. The underlying theory of DMF actuations, device fabrication methods and integration of optical and opto-electronic detectors is discussed in this review. Example applications of such electro-actuation-based DMF devices have also been included, illustrating the various actuation methods and their utility in conducting chip-based laboratory and clinical diagnostic assays.
Highlights
The term ‘droplet microfluidics (DMF)’ is generally associated with the handling of fluidic sample droplets, in the volume range of microliters (10−6 L) to picoliters (10−12 L)
A key attribute of the Droplet microfluidics (DMF) actuation methodology is the rapid and automated handling of fluidic samples, in the form of discrete droplets that are dispensed, transported, merged, split and temperature cycled on patterned substrates [1,2,3,4,5,6,7]
Capillary forces dominate over the inertial effects [1,4], and the majority of droplet actuation methods rely on controlling the interfacial energy at the solid-liquid, liquid-liquid interfaces
Summary
The term ‘droplet microfluidics (DMF)’ is generally associated with the handling of fluidic sample droplets, in the volume range of microliters (10−6 L) to picoliters (10−12 L). There are other methods that rely on the sufficient induction of body forces within the liquid mass, juxtaposed with interfacial forces to create stronger actuation regimes [2,3,6] The approach towards such droplet manipulation in DMF can be broadly classified as passive and active droplet actuation schemes [1]. Been exploited for maneuvering functionalized micro-particles, cells and lipid vesicles for sample preparation and other bio-diagnostic applications [43,46,47,48] Another unique electro-actuation technique, originally investigated as single-phase electrostatic droplet actuation [12,28], requires coplanar arrangement of herringbone-shaped electrodes. Device (reproduced with permission from [7]); (b) droplet actuation using SAW (reproduced with permission from [6]); (c) rapid droplet array dispensing using liquid dielectrophoresis (L-DEP) (reproduced with permission from [49]); (d) continuous droplet transport using droplet-DEP (D-DEP) (reproduced with permission from [3])
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
