My experiments and a review of the physics literature suggested that one would not predict the extreme negative pressures reported in the xylem elements of trees. My view is that either the negative pressures in the xylem are typically overestimated, or plants have a novel mechanism for avoiding bubble formation. Overview of current research I am currently investigating the nature of the glue-like adhesive used by limpets at low tide. These secretions are neither truly solid, like a cement, nor fluid, like the water under a sucker. They are visco-elastic gels, usually based on mucus.
Most people consider viscous gels to be sticky, because that seems intuitively reasonable.
Nevertheless, mucus is typically used as a lubricant. Marine animals are almost invariably coated with a slippery mucus. Mammals use slippery mucus to line their digestive, respiratory, and reproductive tracts. It is impressive that limpets can convert a slippery gel into a powerful adhesive. My research plan is to understand the biochemical changes that trigger this change in mechanical properties.