Astable regimes are common in nonlinear systems ranging from electrooptic devices to cardiac rhythms under environmental stress. Electrosprays exhibit three main axial regimes (dripping, pulsating, and cone-jet). It is generally accepted that the transition between the pulsating and cone-jet regimes is sudden, accompanied by an abruptly enhanced spray current. Here we present an alternative to this scenario, in which the electrospray follows a new chaotic astable path to the cone-jet regime. The astable regime could be explained as a result of transitions between a limit cycle (pulsating regime) and a fixed point (cone-jet regime) in a subcritical Andronov-Hopf bifurcation due to small external perturbations (noise). With the introduction of this regime, a broader view of the diverse axial regimes becomes possible based on nonlinear dynamics that enables their consistent classification.

• Received 1 April 2007

DOI:https://doi.org/10.1103/PhysRevE.76.026320