EWOD Digital Microfluidics for Lab on a Chip

Abstract

This paper presents a brief overview of Electro Wetting On Dielectric (EWOD) microdroplet actuation technology fluidic behaviour. EWOD specifics are compared with other digital microfluidics actuation modes. In particular ease of integration with complex protocols is emphasized. After reviewing the electro-wetting principle and various Electro-Hydro-Dynamic (EHD) phenomena; we compare various EWOD configurations for Lab on a Chip. Two fluid functionalities will be detailed: on-chip droplet dispensing, and mixing. We cover chip architecture and the benefits of organizing these chips as fludic microprocessors. Finally, real time PCR (Polymerase Chain Reaction) within a 64 nl droplet is described as an illustration of a biological application using EWOD.

Digital Microfluidics for Nucleic Acid Amplification

“…Fouillet and co-workers successfully demonstrated the use of a DMF-based chip for single nucleotide polymorphism genotyping in human placental DNA samples [ 25 ]. The group developed a closed configuration device, with a polycarbonate top plate, coated with ITO and Teflon ® .…”

Single-Molecule DNA Amplification and Analysis Using Microfluidics

“…It needs to be noted that other forms of droplet microreactors on chips can also be used to perform DNA amplification and analysis at the single-molecule level, such as droplets using EWOD-based digital microfluidic technology. ,− In 2003, Pollack et al first reported EWOD-based digital microfluidics for real-time PCR applications . It has been shown in their work that the manipulations and the environment inside the EWOD digital microfluidic chip did not inhibit PCR and that the real-time PCR assays were successfully performed in 300 nL droplets using the EWOD chip.…”

“…However, the total time for the PCR test was 55 min, and the total sample volume consumed was 15 μL. Nearly at the same time, Fouillet et al used a droplet-based EWOD digital microfluidic chip to amplify 10 human placental DNA copies in a 64 nL droplet, showing the robustness of the EWOD system with small DNA copy numbers. By integrating the heating on the chip, the PCR cycling can be completed within 15 min.…”

Sensitivity Validation of EWOD Devices for Diagnosis of Early Mortality Syndrome (EMS) in Shrimp Using Colorimetric LAMP–XO Technique

“…In this work, the so-called microfluid technique electrowetting-on-dielectric (EWOD)—sometimes known by its more common name, “digital microfluidics”—was selected for creating LAMP–LOC platforms for the field detection of EMS in shrimp ponds. Today, EWOD devices are commonly used for microdroplet manipulation, i.e., transporting, splitting, mixing, and dispensing [ 24 , 25 , 26 ], and are quite suitable for manipulating the chemical reactants involved in LAMP detection, as mentioned in Table 1 and Table 2 .…”