Massively Multiplexed Electrohydrodynamic Tip Streaming from a Thin Disc

Abstract

We report an experimental study on the multiple tip streaming enabled by an externally wetted thin disc in electric fields. The electrohydrodynamic stress acting on the liquid-air interface triggers an interfacial instability that develops into multiple radial liquid ligaments at the rim of the disc. The scaling law suggests that the wave number is inversely proportional to the square of the peak electric field at the rim, which is determined by the combined thickness of the disc and the attached liquid layer. The thin disc edge effectively intensifies the electric field, which in turn leads to spacing between ligaments as short as 30 μm for ethanol, generating over 1000 cone jets for a 1 cm diam thin disc.