The Joy of 3D Digital Technology for Artists
Danice Chou, Biomedical Engineer, 3D Modeler and 2D Graphic Artist, Biomedical Modeling Inc. •www.danicechou.com
The text and several images from Danice Chou’s presentation at TransCultural Exchange’s 2016 International Conference on Opportunities in the Artsare below.
Now that we've heard about capturing 3D data and modifying it in the digital world, I would like to discuss bringing these designs back into the physical world with modern manufacturing technology.
At Biomedical Modeling we use 3D printing to make custom anatomical models for surgeons, medical device engineers and the occasional artist. Here are two models of blood vessels in the brain that we 3D printed at different scales:
They show the amount of complexity, detail and resolution that can be achieved with this technology.
Today the term “3D printing” is used to refer to a variety of additive manufacturing processes that build an object up layer by layer. Typically, 3D printers are computer controlled and use STL files that contain the surface geometry data of a part. The 3D printer software takes this data and splits it into several cross-sections so it can fabricate each layer.
Each of the jaw models shown below were made with a different type of 3D printing process. Each process has its pros and cons and range of compatible materials.
Additive manufacturing and 3D printing encompasses many different technologies. Rather than get too into technical jargon, I would like to group them into four main types: extrusion, light curing, sintering and binding.
In extrusion, model material, which often exists as spools of filament, is heated up and pushed though nozzles. It is similar to a pastry chef decorating a cake. A robotic arm moves the nozzles around a build platform, depositing rows of material for each layer of a model.
This process is called Fused Deposition Modeling (FDM) and is common among hobbyist and maker communities. The heated material fuses to adjacent material strands as it is deposited from the nozzle. Many desktop FDM printers are limited to one nozzle, so the model must support itself as it is being built. A second nozzle allows for a second supportive material that can later be dissolved away.
Schematic: Custommade, Inc.
Here are some parts made via the FDM process.
While a lot can be achieved with FDM printers, they are essentially limited to one build material and have much more pronounced layer lines than other types of 3D printing.
Some creative approaches to address these limitations include a filament tie-dying technique used to add more colors into an FDM model, and various post-processing methods of smoothing out a model, including manual and chemical polishing as well as painting with other resins to fill in surface gaps.
Because these machines have been widely adapted by the open source and maker communities, people have explored using them to print in different materials (beyond the typically rigid plastics PLA and ABS, which are respectively favored for their biodegradability and strength). Materials like Fenner Drives' Ninjaflex are interesting materials because of their flexibility and elasticity. Others have experimented beyond plastic, modifying printers to extrude materials like chocolate and other foods.
Companies have developed composite filaments that mix materials like wood or metal into plastic filament. Below we have some models printed in a filament called laywood, which was designed to produce models that feel and smell like wood. (Striation patterns can even be burned into the wood adjusting extruder head temperatures while printing.)
Companies like Micron 3DP have been working to develop create extruders that can be used with wider ranges of materials like glass. Last year, a group of research teams from MIT developed a machine for printing in molten glass and displayed their very impressive results at the MIT Media Lab.
Other 3D printers use photo-sensitive plastic resins that react and harden when exposed to UV light. Stereo-lithography or SLA machines do this by using a UV laser to trace layer paths in a tank of uncured liquid resin as a build platform moves up or down between layers.
The resin that is exposed to the laser beam cures into rigid plastic while the remaining material remains as uncured. A network of thin support struts attached to the model is also built. Since they are built in the same material, they must later be broken off mechanically.
When the build is complete, the platform moves to emerge the model from the liquid resin and the part is cleaned. While SLA materials are limited to those that cure with UV light, these machines offer a much higher resolution than extrusion methods.
Here are some jaw models on an SLA machine.
The first image shows models partially submerged in resin during the build. To the right are the models once the build was complete, before cleaning. The red parts on the model were made by using the laser to over-expose the part in specific regions to cause a color change in the material.
While those jaws were made on a higher-end million-dollar machine, more affordable desktop SLA printers also exist, like the Form1 and Form2 by Formlabs. They work with different software and materials, but do offer resins of various colors and even resins that can be used for jewelry casting.
Here is an SLA print of digital artist Bogi Piroth's detailed Bear sculpture. He designed it in a program called Zbrush and had it printed by Mattia Mercante 3D Printing Services. It stands 13 inches tall and was printed in multiple pieces and glued together.
PolyJet 3D printing is another type of light curing method. It uses a print head like those found in regular inkjet printers. Instead of ink, it prints in photo-sensitive plastic resin and cures each printed layer with beams of UV light.
Like color printers, PolyJet printers use multiple cartridges to print in multiple materials. A gel-like or wax material is printed to support the printed model. More cartridges allow for a second model material that can have a different color or flexibility from the first. While this process can be somewhat expensive, it allows for high resolution parts with multiple materials.
The Horse Marionette by designer Michaella Janse van Vuuren (below shows how this technology can be used to print intricate assemblies with moving parts.
Daniel Widrig's Digital Dissection No. 3 shows great detail and the use of different materials.
Nick Ervnck's sculptures get a bit more abstract with color and form.
In another process, a different type of laser is used to melt or fuse together powdered model material. As each layer is built, a platform lowers and a roller passes over to distribute new powder. Non-fused powder supports the part as it is built and is later removed by excavating the part and brushing off excess powder. While this process can be very expensive and have a somewhat gritty finish to raw parts, it can be used with some interesting materials like nylon and metals. While these materials also tend to be more expensive, un-fused material in a powder bed is reusable.
Schematic: Modified from Custommade, Inc.
Here are some intricate pieces that were printed using sintered nylon and gold: a printed ball of chain mail, modern shoe soles and a jewelry pendant, designed respectively by George Hart, Ross Barber and Lionel T. Dean from parts made from sintered nylon and gold.
In 2013, Markus Kayser made news with his Solar Sinter engineering project when he used sunlight in a desert to produce parts made of sand.
This year, a Polish company, Sand Made, aims to release a smaller-scale SLS printer that prints quality parts in sand as well as other materials including polystyrene and wax.
Another type of powder bed printing involves binding. Instead of melting the powder material with a laser, a print head is used to deposit binder that glues the material together. After excavation and cleaning, parts are often dipped into a stronger binder like cyanoacrylate (aka superglue) or epoxy to increase the stability of the part.
Schematic: Modified from Custommade, Inc.
While this process tends to create parts that are more fragile than those created by other technologies, it is relatively inexpensive. Colored ink added to the print-head also allows for deposition of ink onto the surfaces of a part. While we previously saw some color examples with PolyJet printing, the way each method handles color is currently very different. In PolyJet printing, different colors come from the use of a limited range of different resin materials, while files are needed for each color, similar to an ingredients list for each shape that is printed during a build. In this process the color information is handled more like a 3D photo applied to the surface of the part.
Here are some examples of colored prints from process using Z-Corp's Z-Printing and 3D System's ColorJet technologies.
While initially used with a gypsum or plaster material, others have also used this binding process with sand for metal casting. 3D Systems also hopes to expand into the world of culinary art with a printer that uses sugar, water and food dyes.
These centerpiece mathematical models by George W. Hart show off the geometrical complexities, color range and gradients that can be achieved with this process.
On a larger scale, a team with architects Hansmeyer and Dillenberger worked with voxeljet to create a room-sized structure with very complex, intricate detail from a design generated from computer algorithms.
Laminated Object Manufacturing is another type of binding process that selectively glues together sheets of material. The outline of each layer is often cut, while unbound areas are cut or perforated to allow for a kind of blocky excavation process.
Schematic: Modified from Custommade, Inc.
Sometimes LOM is not considered a true additive manufacturing process because of the amount of subtractive cutting involved. Here are two parts printed in paper by MCOR Technologies.
When a part comes off of the printer it is encapsulated in blocks of the trimmed paper that must be carefully removed from the model. While this “weeding” process can require careful manual labor, MCOR's paper printers allow for printing full color surfaces. Both paper and binder in this process are also recyclable and make the material costs very inexpensive compared to other processes. The cardboard sculptures below were created using a process that stray away from 3D printing and additive manufacturing, but still borrows from their technologies.
Similar to 3D printing, these sculptures started from 3D models that were sliced into layer data and cutting instructions for a computer-controlled laser cutter. The process might be described as a kind of laminated object manufacturing that requires a bit more manual assembly.
Rather than focusing on classifications and the often-changing names of all of the different kinds of 3D printing processes, I would like to encourage excitement over the existence and increasing accessibility of all of these tools. With the variety of tools available and their continual development, I hope they offer numerous possible contributions to one's creative process.
As far as places to get started with working in 3D, there are a range of online databases of 3D parts if you want to get some ideas of what other people are doing. Some examples are Thingiverse, Grabcad, Turbosquid and Yobi 3D. Some communities encourage collaboration and the evolution of parts. Meanwhile many museums are beginning to digitize their collections, like Clark Mills’ life mask of Abraham Lincoln, whose data is online via the Smithsonian X 3D.
There are also online marketplaces like Shapeways and i.materialise where artists upload digital designs to be sold as 3D printed products. Nervous System takes an approach to personal customization where a wider range of customers can modify algorithmically-driven jewelry designs by controlling parameters like mesh sizes and shape curvature and order their personalized parts.
If you would like to take a more hands-on approach and do not have an immediate need for higher end 3D printing tools, I would encourage the involvement in community resources and maker spaces. Here you might find access to 3D printers that you aren't quite ready to invest in as a personal resource. Many of these spaces offer tutorial programs as well as a community of people to interact with as you explore different technologies. Artisan's Asylum in Somerville, Cambridge Hackspace and Watertown Hatch are a few local resources around Boston.
There are also online directories like Makerspace.com and Hackerspaces.org for finding maker spaces and communities in other locations. 3D Hubs is a site for finding local 3D printing resources, where anyone with a 3D printer who is willing to provide print services can list their information for potential customers or collaborators.
While modern technology is very exciting and opens up a lot of possibilities for the 3D artist, I would like to shed some light on its less exciting realities and limitations. Here is a montage of some failed 3D printing builds.
Technical errors do happen. Even when things go smoothly, a lot of work can go into the cleanup and post-processing of a printed part to make it look as impressive or as beautiful as some of the examples that we have seen today.
If you are in a position where you would like more involvement in the 3D printing of your creations, but would like a lot of the technical details to be mapped out by someone else, I would encourage reaching out to local service bureaus and consultants.
Many people prefer to collaborate with local providers who can offer more feedback and guidance. They can provide professional assistance and their expertise in 3D printing to help you select the right technology or to help you adjust your designs for your particular needs and desired results. 3D Printsmith and Munson3D, currently represented on this stage, provide such services in the Boston area.
Finally, I would like to close with another look at the brain model project that I first showed on my title slide. To the right is a life-sized brain vessel model with its wax support material intact. To the left is a cast-able printed model of the white matter of the same brain.