Design, Fabrication, and Characterization of Linear Multiplexed Electrospray Atomizers Micro-Machined from Metal and Polymers

Abstract

Multiplexed electrospray is a promising aerosol generation technique to produce high throughput quasi-monodisperse droplets in the nanometer and micron size range. Here we report the design, fabrication, analysis, and performance of a linear electrospray (LINES) system. The fabrication of the nozzle array is based on a precision computer numerical control (CNC) micromachining platform with 1-micron resolution. This rapid prototyping approach offers the flexibility of creating devices from a wide range of materials including metals and polymers with packing densities on par with silicon microfabrication at 20 sources/cm for LINES devices and 460 sources/cm 2 for the two-dimensional array. The LINES device uses a slot extractor design to simplify alignment and enhance operation robustness. We also used dummy nozzles (posts without fluidic channels) to offset edge effect on electric field and improved droplet size uniformity. We derived the approximate spray expansion model from charge conservation and Gauss' law. We applied the line-of-charge approximation to establish scaling laws for prescribing operating conditions. The devices show excellent droplet size uniformity from source to source, with relative standard deviation (RSD) of primary droplets <3%.

Gas-focused liquid microjets from a slit

“…A four-nozzle linear array was machined using a precision drilling and milling process out of aluminum. 19 The nozzles ( Fig. 9(a)) have equal spacing of 500 µm, outer diameter (OD) of 200 µm, and inner diameter (ID) of 100 µm.…”

Coaxial Electrohydrodynamic Atomization for the Production of Drug-Loaded Micro/Nanoparticles

“…Parhizkar et al proved that a circularly distributed needle array more easily achieved high particle size uniformity in comparison with a rectangular array while a lower voltage was required under the same operating conditions [ 28 ]. The scaled-up electrospray system has been applied in agriculture, sanitation, and other industrial applications [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”

Impacting and Wetting Dynamics of Single Polysilazane Droplet on Inconel Surface

“…The substrate material in this study is Inconel and it is one kind of typical materials used in gas turbine engines [4]. In the PDC processing, silicone-based polymers are first deposited on the substrate through spray coating [5]. Then, the conversion from the liquid polymer to solid ceramics takes place via thermal, chemical, or radiative heat treatment pro-cesses.…”