Birth and growth of cavitation bubbles within water under tension   confined in a simple synthetic tree
  Water under tension, as can be found in several systems including tree vessels, is metastable. Cavitation can spontaneously occur, nucleating a bubble. We investigate the dynamics of spon- taneous or triggered cavitation inside water filled microcavities of a hydrogel. Results show that a stable bubble is created in only a microsecond timescale, after transient oscillations. Then, a diffusion driven expansion leads to filling of the cavity. Analysis reveals that the nucleation of a bubble releases a tension of several tens of MPa, and a simple model captures the different time scales of the expansion process. 
Olivier Vincent, Philippe Marmottant, Pedro A. Quinto-Su and   Claus-Dieter Ohl
physics.flu-dyn cond-mat.other