3-D printing of Thanksgiving and Christmas pumpkins and snowmen has taught me new skills. Some of the objects are complex, especially the ornaments. Notice the tip of the red one. The gold bell has a working clapper inside. The big snowman (8 ” tall) required printing 18 separate parts with five different filament colors and then assembling them. The shorter snowman was printed as a single piece. My wife added colors using magic markers. Filament, the ink of the 3-D printer, comes in numerous compositions and colors. I use PLA (polylactic acid). It is thermoplastic polyester, similar to what you might use in a weed wacker.
Aside from holiday creations, there are major advances coming in healthcare using 3-D printing. One area is called regenerative medicine, the process of replacing or “regenerating” human cells, tissues , or organs to restore or establish normal function. The ink used in some regenerative medicine includes human stem cells. This is called bioink.
Bioprinting starts by obtaining the anatomical structure of the target tissue. This is done by starting with imaging techniques such as computerized tomography (CT) and magnetic resonance imaging (MRI). Specialized software is then used to translate the image to a 3-D computer aided design (CAD) image revealing cross-sectional layers which a 3-D printer can print layer-by-layer, just like the snowman and Christmas tree.
In my opinion, bioprinting is one of the next big things, and we will be amazed at what is being done. Numerous printing methods are emerging to print human tissue including inkjet 3D bioprinting, micro-extrusion 3D bioprinting, laser-assisted 3D bioprinting, and stereo-lithography. After printing, the constructed tissue is post-processed in a bioreactor to recreate an in vivo (in a human or animal) environment to maintain the tissue viability and allow it to mature. If you are interested in regenerative medicine, see Health Attitude: Unraveling and Solving the Complexities of Healthcare.
Merry Christmas and Happy Holidays!