Evaporation Dynamics of Sessile Droplets

The evaporation of sessile droplets encompasses a rich interplay between interfacial physics, thermodynamics and transport processes. As a droplet rests on a solid surface, solvent loss generates capillary-driven outward flows, temperature- or concentration-induced Marangoni circulations, and fluctuations of the contact line through pinning and depinning sequences. These mechanisms dictate characteristic evaporation modes—constant contact radius, constant contact angle and stick–slide—and determine droplet lifetime, flow field and deposit morphology. The resulting patterns, from coffee-ring stains to homogeneous films, underpin applications in inkjet printing, coatings, surface patterning, diagnostic assays and heat transfer. Recent advances in high-speed imaging, microfluidics and mathematical modelling are progressively linking microscale interfacial dynamics to macroscale outcomes, enabling tailored deposit structures and controlled evaporation across diverse substrates and ambient conditions.

Research from Nature Portfolio

Recent studies have revealed universal scaling laws and novel deposition regimes in evaporating droplets. Investigation of non-spherical drop geometries demonstrated a shape-independent law for evaporation rate, showing that local curvature directs internal flows and preferential particle deposition. In a kinetics-controlled regime, rapid interface recession relative to particle diffusion leads to surface jamming and suppression of the coffee-ring, yielding uniform particle films. Furthermore, the addition of surfactant-like polymers has been shown to induce centripetal Marangoni vortices, periodically alternating pinning and depinning to produce regular multi-ring deposits and mitigate ring-like stains.

Evaporation Dynamics of Sessile Droplets publication trend

The graph below shows the total number of articles in evaporation dynamics of sessile droplets across all publications each year (not limited to Nature Index journals).

Technical terms

Sessile droplet: A liquid drop resting on a solid substrate without external confinement.

Contact line: The boundary where liquid, solid and vapour phases meet.

Contact angle: The angle formed at the contact line between the liquid–vapour interface and the solid surface.

Coffee-ring effect: The tendency for dispersed particles to migrate to the droplet periphery during evaporation, producing a ring-shaped deposit.

Marangoni flow: Fluid motion driven by gradients in surface tension, often arising from temperature or concentration differences.

Stick–slide mode: An evaporation regime characterised by alternating pinning and receding of the contact line.

References

1. Evaporation of Sessile Droplets. Annual Review of Fluid Mechanics (2022).
2. Dynamics and universal scaling law in geometrically-controlled sessile drop evaporation. Nature Communications (2017).
3. Rate-dependent interface capture beyond the coffee-ring effect. Scientific Reports (2016).
4. Altering the coffee-ring effect by adding a surfactant-like viscous polymer solution. Scientific Reports (2017).
5. Drying Drops of Colloidal Dispersions. Annual Review of Chemical and Biomolecular Engineering (2023).
6. On the lifetimes of evaporating droplets with related initial and receding contact angles. Physics of Fluids (2015).
7. Simultaneous spreading and evaporation: Recent developments. Advances in Colloid and Interface Science (2013).