Digital Microfluidics and Electrowetting Technologies

Digital microfluidics encompasses the precise manipulation of discrete droplets on an array of electrodes, typically by modulating interfacial tension through applied electric fields. Electrowetting on dielectric platforms exploits voltage-controlled changes in contact angle to dispense, transport, split and merge droplets with microlitre to picolitre volumes. This approach enables programmable microreactors, assay automation and integration of multiple unit operations within a compact footprint. Advances in materials, dielectric coatings and electrode architectures have improved reliability, reduced power consumption and broadened the range of compatible liquids. The closed-chip architectures of conventional digital microfluidics offer high levels of control for biochemical assays and single-cell studies, while emerging open-system formats provide direct access to droplets at the air–liquid interface. Together, these technologies underpin lab-on-a-chip platforms for diagnostics, high-throughput screening, synthetic chemistry and adaptive optics, offering rapid turnaround, low reagent consumption and seamless integration with detection modalities.

Research from Nature Portfolio

Open-system droplet microfluidics has been shown to bridge the gap between high-precision manipulation and user accessibility by utilising interfacial forces to move picolitre-scale droplets without pumps or tubing. Such platforms leverage patterned electrodes and surface treatments to perform combinatorial chemistry, on-demand mixing and cell culture studies, all with simple fabrication and scalable assembly. A second body of work has introduced a fully automated droplet robot based on electret-induced polarization, enabling voltage-driven actuation of diverse aqueous and non-aqueous liquids without compromising biological activity. This approach permits handling of living cells, proteins and complex fluids in volumes from nanolitres to millilitres, and integrates seamlessly into automated workflows for biochemical experimentation.

Digital Microfluidics and Electrowetting Technologies publication trend

The graph below shows the total number of articles in digital microfluidics and electrowetting technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Digital microfluidics: Manipulation of discrete droplets via programmable electrode arrays.

Electrowetting on dielectric (EWOD): Voltage-induced modulation of a droplet’s contact angle on a dielectric-coated electrode.

Contact angle: The angle at which a liquid–vapour interface meets a solid surface, determining wettability.

Electret-induced polarization on droplet (EPD): A droplet actuation mechanism using permanent surface charges to drive liquid motion without external bias electrodes.

Young-Lippmann equation: A relation predicting contact angle change under applied voltage based on interfacial tension and dielectric properties.

References

1. Miniaturizing chemistry and biology using droplets in open systems. Nature Reviews Chemistry (2023).
2. A droplet robotic system enabled by electret-induced polarization on droplet. Nature Communications (2024).
3. Non-aqueous electrowetting liquid lens with centimeter-level large aperture based on dielectric failure suppression principle. Light: Science & Applications (2025).
4. Relation between Double Layer Structure, Capacitance, and Surface Tension in Electrowetting of Graphene and Aqueous Electrolytes. Journal of the American Chemical Society (2023).