Pulsation of electrified jet in capillary microfluidics

Abstract

In this work, we investigate the pulsation of an electrically charged jet surrounded by an immiscible dielectric liquid in flow-focusing capillary microfluidics. We have characterized a low-frequency large-amplitude pulsation and a high-frequency small-amplitude pulsation, respectively. The former, due to the unbalanced charge and fluid transportation is responsible for generating droplets with a broad size distribution. The latter is intrinsic and produces droplets with a relatively narrow size distribution. Moreover, the average size of the final droplets can be tuned via the intrinsic pulsating frequency through changing the diameter of the emitted liquid jet. Our results provide degree of control over the emulsion droplets with submicron sizes generated in microfluidic-electrospray platform.

Electrohydrodynamics of droplets and jets in multiphase microsystems

“…Under this circumstance, the combination of the electrostatic and the inertial effect balances the surface tension effect, We o 1 and Ca e B 1. 28,[157][158][159] At a high charging level, the electric stress is sufficiently strong to reach Ca e B 1, the electrostatic and the surface tension effects balance, and the liquid meniscus deforms into a conical shape with a thin jet emitting from the tip of the cone. Within a narrow combination of flow rates and applied voltages, the cone shape is steady and a fine jet emits continuously, which is also known as the steady cone-jet mode (Fig.…”

Wide bandgap semiconductor nanomembranes as a long-term biointerface for flexible, implanted neuromodulator

“…Preclinical outcomes over the last decade have documented the remarkable development and innovation of advanced bioimplantable electronics for neuron stimulation ( 12 – 15 ). As such, there are two current mainstream neuromodulation systems: 1) intraneural electrodes, which can penetrate deeply into neural tissues, and 2) extraneural electrodes, which enable conformal contacts with the curvilinear surface of neural tissue.…”

“…Nevertheless, extraneural approaches are preferred due to a lower risk of nerve damage and potentially higher resolution for spatial physiological mapping ( 17 ). Flexible electronics are considered the backbone technology for the realization of modern extraneural stimulators, in which the integration of soft semiconductors, ultrathin metallic interconnectors, and polymeric substrates offers ideal mechanical matching between functional devices and tissues ( 6 , 13 , 14 , 18 ). Several types of distributed arrays of electrodes on soft substrates, combined with wireless communication modules (e.g., near-field communication), have shown potential for the monitoring and treatment of neural disorders ( 19 , 20 ).…”