Squid and cuttlefish suckers are based on a plunger-like design, which works well for high strength and rapid attachment, but doesn't have the dexterity of an octopus sucker. Because negative absolute pressures are possible, the use of suction adhesion may be more widespread than was currently believed. I demonstrated that limpets also use suction adhesion and can produce negative pressures. Many researchers had dismissed suction as a mechanism because of the great strength of limpet adhesion. Although limpets use suction, they also use a glue-like adhesive.
Limpets use suction at high tide, then switch to gluing when the tide goes out.
This pattern of alternating between attachment mechanisms has not been previously considered, and may be common in animals other than limpets. My work on negative pressures led me to address the question of sap ascent in trees. 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.