A new form of 3D printing technology can make embeddedable, plush toys.
3D printing has grown leaps and bounds over the last couple of years, not only in terms of the gadgets themselves, but the filaments they are capable of extruding as well. Still though, most consumer-grade 3D printers only construct objects comprised of rigid and hard materials (like plastics, ceramics or metal) fused together. That was until now. A group of researchers from Disney, Cornell University and Carnegie Mellon University have recently developed a new 3D printing technique that creates items out of layers of felt.
“Consumers increasingly prefer high quality and beautiful bespoke objects, as evidenced by the success of websites such as Etsy,” the team elaborates upon the inspiration of the project. “However, these websites typically require individual craftspeople to produce such objects by hand. New additive manufacturing technologies (more commonly known as 3D printing) provide an opportunity to manufacture highly custom objects on demand.”
The so-called Layered Fabric 3D Printer works along principles similar to those used in polymer deposition. A 3D model is broken down into slices, which are translated into the printer. This is where the two techniques diverge. Rather than being laid down by an extruder nozzle, this method uses a laser to cut the outline of each layer from a roll of heat-activated adhesive fabric that correspond to the sliced layers. The fabric is fed to the bottom face of the bed by rollers mounted to the sides, and held in place by a vacuum during cutting. This layer is then transferred onto the printer’s build platform, where it is activated by a warm disc on the machine’s print head. This process is then repeated until the object is fully “printed,” whereupon completion, the result is a block-like figure that is manually peeled, revealing a soft and flexible layered object.
The printer is also multi-material, and can automatically integrate two types of fabric into a single print. Meaning, conductive fabric can be embedded in a print to create a capacitive touch input or electric circuit paths. “For example, objects with printed ‘wiring’ can be constructed using conductive fabric. This ‘wiring’ is completely flexible since it is formed with, and entirely embedded inside of, fabric sheets,” the team adds. “We have used this capability in several proof-of-concept demonstration objects including a soft cell phone case which contains a printed fabric coil capable of harvesting power from the NFC hardware of an off-the-shelf cell phone.”
By using conductive fabric as one of their material feeds, the researchers were able to make custom-printed capacitive sensors as a part of a normal print, including a touch-enabled necklace pendent in the form of a soft starfish connected to an Arduino Lilypad (ATmega328) and a capacitive sensor configured as a slider linked to an off-the-shelf Teensy MCU.
Much like a number of other traditional printers available today, the Layered Fabric 3D Printer is powered by an Arduino Mega 2560 (ATmega2560) driving a RAMPS 1.4 control board with Repetier firmware. On the software side, the project employs Repetier-Host v0.95 with no modification and Slic3r v1.1.7. The build volume for the current prototype is 10” x 10” x 10”, though the team does note that larger-sized devices could be easily constructed using this same design.
To first test out its approach of crafting on-demand plush toys, the team constructed a 2.5-inch Stanford bunny in roughly two and a half hours. Interestingly enough, unlike conventional printers where printing and filling the model are the most laborious parts, with this machine, movement of the bonding platform and the bonding steps consume the most time.
“It consists of 32 layers of acrylic felt fabric resulting in a 64mm high final product. Despite the relatively thick 2mm felt used in the print, it preserved most of the details in the underlying 3D digital model like the nose and ears. Also notice the relatively com- plex overhanging shape in the ears of the bunny. Because of the cutting strategy we used, fabric from the bounding box area of the previous layer serves as support for overhangs, including very small and sharply overhung features such as these.”
When all is said and done, the researchers are looking to usher in a new way of layer-based 3D fabric printing that can form precise, yet soft and deformable 3D objects from rolls of off-the-shelf fabric. As TechCrunch notes, “It’s as much a laser cutter as it is a 3D printer.” Nevertheless, it’s still extremely cool — and AVR powered!
Want to learn more? You can read the entire paper from Disney Research, Cornell University and Carnegie Mellon here.
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