The RepRapMicron (also µRepRap) is pretty much the microscopic take on what RepRap did for more macroscale manufacturing, with the most recent innovation being a UV print head, called the PIKA UV Head. What this does is use off-the-shelf optical fiber and UV LED modules to create 3D structures in-situ in a UV resin, which allows quite small structures to be printed, down to a resolution of around 9 µm.
More photos of prints can be found on the blog page with links to YouTube videos. Of course, it’s a bit tricky to get clean photos of a 3D print that’s small enough to be lost forever if you so much as sneeze or breathe too hard.
For the UV head assembly a single mode fiber optic cable was used in the form of a regular patch cord that was cut a bit with a hacksaw. This was used in combination with a “3W” UV LED module, which may or may not be its correct rating, but it was definitely able to cure the SLA resin. The resin used was regular eSun standard resin.
After that, you have to do the typical SLA post-processing, including cleaning liquid resin – both the part and the fiber – and curing the part. So far the results are pretty decent, with overhangs still being a weak point that will be addressed in future versions.