A new method for deflecting liquid microjets

Abstract

A new method is reported for deflecting a microscopic jet emanating from a nozzle away from the nozzle’s axis of symmetry. It relies on putting energy into the jet through an asymmetric heater embedded in the nozzle. This novel phenomenon is probed theoretically. It is shown that jet deflection is set by the competition among three effects. Two of these can be attributed to the variation with temperature of surface tension and the third to that of viscosity. Whether the contact line is fixed or free is shown to profoundly impact the extent of jet deflection at a given flow rate.

Dynamics of Cryogenic Jets: Non-Rayleigh Breakup and Onset of Nonaxisymmetric Motions

“…Systematic studies reveal larger jet deflections from the vertical axis with decreasing jet diameter and velocity or TPC pressure. We note that asymmetric heating has been employed by another group to deflect liquid microjets [23], however, we report spontaneous deflection of symmetrically produced jets.…”

Small‐scale free surface flows with breakup: Drop formation and emerging applications

“…Exciting applications include the use of light to cause changes in surface tension to induce drop pinch-off (Shin and Abbott, 1999) and heat to cause surface tension and viscosity gradients to induce microjet deflection and breakup (Chwalek et al, 2002).…”

“…They also require that inks used in them can be charged. A recent development (Chwalek et al, 2002) appears to overcome many of these drawbacks. These authors report that a liquid jet can be deflected by asymmetrically heating a microscopic nozzle manufactured using standard silicon processing technology.…”

The spreading of a viscous microdrop on a solid surface

“…There is increasing engineering and industrial interest in micro-fluidics, for example with the development of lab-on-chip devices, MEMS, electrospraying, micro-ink-jet printing, and the manufacture of pharmaceuticals, fine chemicals, small particles and powders. See Ahn et al (2005), Anagnostopoulos et al (2003), Anna et al (2005), Basaran (2002), Brenner et al (2005), Chatterjee et al (2005), Chwalek et al (2002), Daneshbod et al (2005), Delametter et al (2002), Dupont et al (2005), Furlani et al (2001), Furlani (2005a, Jang et al (2005), Kerbage et al (2005), Krupenkin et al (2005), Loscertales et al (2002), Morini et al (2005), Moseler and Landman (2000), Mukherjee et al (2005), Quake (2005), Sirringhaus et al (2000), Tabeling et al (2005), Wang et al (2005), Wu et al (2005), Xuan et al (2005), Ye et al (2005) and Zheng et al (2005) for some varied examples of some of the most recent work in microfluidics in other problems.…”