Send to

Choose Destination
Proc Natl Acad Sci U S A. 2013 Aug 13;110(33):13255-60. doi: 10.1073/pnas.1305886110. Epub 2013 Jul 29.

Open-atmosphere sustenance of highly volatile attoliter-size droplets on surfaces.

Author information

Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, Eidgenössische Technische Hochschule Zürich (ETH Zurich), CH-8092 Zurich, Switzerland.


The controlled formation and handling of minute liquid volumes on surfaces is essential to the success of microfluidics in biology, chemistry, and materials applications. Even though current methods have demonstrated their potential in a variety of experimental assays, there remain significant difficulties concerning breadth of applicability, standardization, throughput, and economics. Here we introduce a unique microfluidic paradigm in which microscopic volatile droplets are formed, sustained, and manipulated in size and content at any desired spot on unpatterned substrates. Their sustainability is warranted by continuous replacement of the rapidly vaporizing sessile fluid through controlled equivalent volume deposition of smaller discrete liquid entities by an electrohydrodynamic nanodripping process. Using nanoparticle inks we show that the concentration of solutes in so-stabilized droplets can be linearly increased at isochoric conditions and user-defined rates. An intriguing insensitivity of the droplet shape toward surface heterogeneities ensures robustness and experimental reproducibility, even when handling attoliter quantities. The unique capabilities and technical simplicity of the presented method introduce a high degree of flexibility and make it pertinent to a diverse range of applications.


digital microfluidics; noncontact printing; sessile droplets

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center