Additively manufactured MEMS multiplexed coaxial electrospray sources for high-throughput, uniform generation of core–shell microparticles

Abstract

This study reports the first MEMS multiplexed coaxial electrospray sources in the literature. Coaxial electrospraying is a microencapsulation technology based on electrohydrodynamic jetting of two immiscible liquids, which allows precise control with low size variation of the geometry of the core-shell particles it generates, which is of great importance in numerous biomedical and engineering applications, e.g., drug delivery and self-healing composites. By implementing monolithic planar arrays of miniaturized coaxial electrospray emitters that work uniformly in parallel, the throughput of the compound microdroplet source is greatly increased, making the microencapsulation technology compatible with low-cost commercial applications. Miniaturized core-shell particle generators with up to 25 coaxial electrospray emitters (25 emitters cm) were fabricated via stereolithography, which is an additive manufacturing process that can create complex microfluidic devices at a small fraction of the cost per device and fabrication time associated with silicon-based counterparts. The characterization of devices with the same emitter structure but different array sizes demonstrates uniform array operation. Moreover, the data demonstrate that the per-emitter current is approximately proportional to the square root of the flow rate of the driving liquid, and it is independent of the flow rate of the driven liquid, as predicted by the theory. The core/shell diameters and the size distribution of the generated compound microparticles can be modulated by controlling the flow rates fed to the emitters.

Hollow Polycaprolactone Microspheres with/without a Single Surface Hole by Co-Electrospraying

“…It is also noteworthy that the yield of the co-electrospraying process is low, but the yield can be enhanced by novel spinnerets. 41 , 48 − 51 …”

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

“…Unlike uniaxial electrospraying, there have been few studies about microarray sources for coaxial electrospray. As we know, research about MEMS multiplexed coaxial electrospray was reported in 2016 [36]. Core-shell particle generators with up to 25 coaxial ejection emitters (25 emitters cm −2 ) were 3D-printed using stereolithography (Figure 3).…”

Controlling of Electrospray Deposition for Micropatterns

“…Several techniques have been developed in the fabrication of micro/nano-particles, such as photolithography, ink jetting, plasma spraying, and pulsed laser deposition [ 1 , 2 ]. Compared with other techniques, electrospray is an attractive method for the fabrication of micropatterns owing to the advantages of simple equipment, low cost, flexibility, simple process, and versatile material compatibility, which lead to enormous potential applications in the fields of sensors [ 3 ], biomedicine [ 4 ], micromanufacturing [ 5 ], and flexible electronics [ 6 ].…”