Probing the Liquid Vacuum Interface
2014 R&D 100 Winner
Important scientific studies require precise knowledge of the unique properties at the interface between liquids and solids or at the liquid surface itself. Analyzing these properties has proven difficult because many key analytical instruments are vacuum-based. In such instruments, liquids normally evaporate before they can be analyzed. To overcome this problem, scientists have used sample holders to position liquids for analysis, but such holders are expensive and designed to fit a single instrument; they also require specially designed cells for each experiment. Scientists also have tried freezing or drying samples for analysis in a static state, but always with the question as to whether different results would have been achieved if the liquid was in its natural state.
Pacific Northwest National Laboratory has developed SALVI: System for Analysis at the Liquid Vacuum Interface, a lab-on-a-chip solution, to meet the needs of such studies. SALVI is a unique, self-contained, portable analytical tool that, for the first time, enables vacuum-based scientific instruments such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) to analyze liquid surfaces in their natural state at the molecular level. Using as little as two drops, or 100 µL, of liquid and requiring minimal sample preparation and no modifications to scientific instruments, SALVI allows scientists to understand complex liquids and develop advanced solutions to challenging problems. The depth of analysis within the sample ranges from a few nanometers to 1 µm, depending on the instrument supported.
Pacific Northwest National Laboratory
|Pacific Northwest National Laboratory's SALVI development team. Back row (l-r): Martin Iedema, Matthew Marshall, Bingwen Liu. Front row (l-r): James Cowin, Xiao-Ying Yu, Zihua Zhu and Li Yang.|
The SALVI: System for Analysis at the Liquid Vacuum Interface Development Team from Pacific Northwest National Laboratory
Xiao-Ying Yu, Principal Investigator
James P. Cowin
Martin J. Iedema
Matthew J. Marshall