Researchers at MIT have used 3D printing to open the door to low-cost, scalable, and consistent generation of microencapsulated particles, at a fraction of the time and cost usually required. Microencapsulation is the process of encasing particles of one material (a core) within another material (a shell) and has applications in pharmaceuticals, self-healing materials, and dye-based solar cells, among others. But the main problem with the process was that it was that it was slow and didn’t scale, and it was therefore expensive and limited to high-value applications only. With some smart design and stereolithography (SLA) 3D printing, that changed. The researchers are not 3D printing these just because they can; they are printing the arrays because it’s the only way they can be made.
A standard manufacturing process for microspheres is coaxial electrospraying, where electrostatic forces and a specialized nozzle are used to encapsulate particles as they emerge from an aperture. Unfortunately, current methods have very low throughput because they have only one emitter, and must choose between low flow rate, or consistent particle size.
The researchers developed a method using a 3D printed array that is not only scalable, but consistent in output. 3D printing was needed to make the complex network of channels required for uniform operation, all at a fraction of the usual cost and fabrication time involved in testing and developing such devices.
No mention of which SLA printer was used, but the detailed report says “The devices were fabricated using a high-resolution SLA printer (pixelation ∼25 μm) with a layer height equal to 25 μm and absolute tolerances in the x–y and z directions equal to 50 μm and 125 μm, respectively” and that the printed material is an opaque green. Do those specs sound familiar to anyone?