What 3D-Printed Electrospray Emitters Are—and Why They Matter
3D-printed triaxial electrospray emitters are miniature nozzle arrays that use electric fields to turn three separate, non-mixing liquids into uniform, multilayer droplets, creating precision microparticles for drug delivery, biosensing, self-healing materials, and tissue regeneration without needing conventional cleanroom-based microfabrication. Electrospraying relies on tiny nozzles, fractions of a millimeter wide, that produce droplets smaller than those formed by mechanical spraying. In a triaxial design, three concentric channels feed three immiscible liquids into each nozzle, forming a controlled shell–middle–core structure. MIT researchers have now shown that these complex devices can be produced through biomedical 3D printing instead of semiconductor processes. Their 3D-printed arrays deliver 16 nozzles on a one-square-centimeter footprint, with internal microchannels that keep flow uniform across emitters. According to MIT’s Microsystems Technology Laboratories, “we couldn’t make a device like this in a semiconductor cleanroom,” underscoring the shift in where high-end microparticle manufacturing can now occur.
From Cleanrooms to 3D Printers: A Shift in Microparticle Manufacturing
Electrospray emitters have long been tied to expensive microfabrication workflows, fabricated in semiconductor-level cleanrooms that take months to deliver complex arrays. Their miniaturized features and strict uniformity requirements made alternatives rare, and there were no reports of miniaturized triaxial arrays built this way. MIT’s new approach turns that assumption on its head. Using vat photopolymerization—a form of high-resolution resin biomedical 3D printing—the team prints complete triaxial electrospray emitter arrays in a single step. Layers as thin as 25 micrometers, far smaller than a human hair, let the printer sculpt the intricate, three-dimensional microchannel network needed to feed three fluids to each nozzle. The result is a compact 3D-printed drug delivery platform that maintains emitter precision while cutting fabrication time to hours instead of months. For microparticle manufacturing, this marks a shift from centralized, cleanroom-limited production toward distributed labs equipped with advanced desktop 3D printers.
Precision Multilayer Droplets for Advanced Drug-Delivery Systems
The promise of these 3D-printed electrospray emitters lies in how they shape multilayer microparticles. Each triaxial nozzle produces three-layer droplets from immiscible liquids, which can then solidify into structured particles. For 3D-printed drug delivery, that means an outer shell, an intermediate barrier, and a core payload can each be tuned separately. One example described by the researchers uses an outer layer that erodes in the stomach, revealing a second layer that controls the release of a medicinal core to a targeted area of the intestines. Uniform droplet size is crucial here: consistent particles help ensure predictable dosing profiles and reliable time-release behavior. The 16-nozzle array, occupying about one square centimeter, can manufacture these particles at scale, supporting applications from time-release pharmaceutical capsules to biosensors and artificial cells for tissue regeneration. In effect, the emitters act as a programmable factory for multilayer therapeutic and diagnostic particles.
Scaling Up: Modular Arrays and Accessible Device Design
Beyond the initial 16-nozzle prototype, the design of MIT’s 3D-printed electrospray emitters is modular. Arrays can be tiled to expand production capacity while preserving emitter density. As lead researcher Luis Fernando Velásquez-García notes, their work demonstrates “emitter densities of 16 emitters per square centimeter,” and the same pattern could theoretically be expanded to around 15,000 emitters over a square foot. This scalability is central to making electrospray-based microparticle manufacturing economically viable. Internal coiled microchannels distribute three fluids evenly to each nozzle, reducing the risk of some emitters running dry or producing off-spec droplets. Because these features are embedded in a single 3D-printed block, there is no need for laborious assembly or alignment of tiny parts. The one-step fabrication process also simplifies iteration: labs can tweak channel geometry, nozzle spacing, or outlet shape in CAD and print new arrays within hours, accelerating experimentation and optimization.
Democratizing Microparticle Production and Personalized Medicine
By cutting out the cleanroom, MIT’s 3D-printed electrospray emitters open microparticle manufacturing to a broader range of users. Smaller biotech companies, academic labs, and hospital-based research groups can, in principle, experiment with targeted and time-release drug carriers using advanced resin printers rather than semiconductor fabrication lines. This aligns with Velásquez-García’s stated goal to “democratize this technology so the benefits can touch many more people.” For personalized medicine, the ability to print device variants quickly suggests a path toward patient-specific microparticle formulations, tuned for dose, release timing, or tissue targeting. The same platform could support self-healing composites that release repair agents on demand, along with biosensors carrying multiple chemical markers in distinct layers. As biomedical 3D printing matures, these electrospray emitters hint at a future in which precision 3D-printed drug delivery systems are designed digitally, manufactured on the benchtop, and tailored to individual clinical or research needs.
