Until recently, the smallest commercial build size for a typical 3D printer was 5 x 5 x 5 in. or close to it. Researchers have gone smaller, printer micro motors and actuators years ago, but none of those systems reached the commercial level. Additive manufacturing starts to lose its appeal as parts get smaller because of the challenges with precision and accuracy that have stymied innovation for engineers and manufacturers looking to develop small, high-resolution parts. But that’s beginning to change as researchers solve many of these challenges.
Thus, 3D printers that build in the micro and nano sizes are emerging. In many cases, such 3D printers can be an alternative to the use of micro-molding.
Much of this development is driven by medical applications, especially those in the micro-optic sector, which is constantly increasing the demand for smaller, higher quality, and more versatile micro-optics. Micro-optic development, along with developments in compact sensors and illumination methods, is used to refine devices such as endoscopes and various invasive camera applications.
Here’s a look at three developers of micro-scale and smaller 3D printers:
Boston Micro Fabrication (BMF), Boston, recently introduced a microscale 3D printer. The MicroArch is a DLP based 3D printer that operates in a top-down process.
The light source is on the top. But in between the light source and the resin is a high precision optics system that delivers the high resolution. Then, the XYZ stage movement is precise. The combination of the optics and the movement and then software and materials enables the microArch to offer resolutions of two microns. So that means you can get accuracy in the 10 to 20 micron range.
Nanofabrica, Israel, offers a micron-level resolution additive manufacturing technology that operates cost-effectively and repeatably. Its 3D printers can produce cylindrical micro lens that are 20 microns high and 100 microns wide. Surface roughness is on the order of 1 micron, and there are 3D printing materials that are 80% transparent for visible light.
These 3D printers can also build jigs and fixtures for optical alignment, optical connectors for optical fibers, fiber optic ferrules and other small related elements, and optical elements such as lenses and prisms.
Nanoscribe, Germany, developed the Photonic Professional GT2, a 3D printer that uses two-photon polymerization (2PP) to produce filigree structures of nearly any 3D shape. These shapes include crystal lattices, porous scaffolds, and parts with smooth contours, sharp edges, undercuts and bridges.
The smallest lateral feature size is 160 nm. This printer is suitable for print volumes < 0.1 mm³. The applications it suits include microfluidics, biomedical engineering, micro-electro-mechanical systems, micro-optics, and nanostructures among others.
The maximum XY feature size is 160 nm typical with 200 nm specified. The finest XY resolution is 400 nm typical with 500 nm specified. Layer distance is 0.3 to 5.0 micrometers. Maximum object height is 8 mm, and the build volume is 100 x 100 x 8 mm3.
