Most students will work with a plastic when making things with a 3D printer, but that is only scratching the surface of materials that can be used in these machines. This book takes a look at the different materials that can be used by 3D printers, what those materials can make, and the advantages and disadvantages for each.
The intelligent design of origami models continues to inspire new developments in 3D printing. At Case Western Reserve University (CWRU) in Cleveland, Ohio, a team of researchers led by assistant professor Kiju Lee have created the TWIsted TowEr Robot (TWISTER) mechanism.
Based on the twisted tower originally designed by Mihoko Tachibana, the mechanism is inspiring the creation of soft robotic arms and all-terrain exploration vehicles.
Paper and plastic
The appeal of the age-old art of paper folding is in the versatility it brings to minimal materials. By correctly folding a single sheet of paper, artists can create solid objects that move, but that can also be disassembled to their original state. The same is true when working with other materials, such as polymers.
The Lee team’s TWISTER mechanism follows a composition of polygons and other geometric shapes, culminating in a tower that can bend freely in all directions. It is a multimaterial design, 3D printed on a Stratasys Objet350 Connex3 in VeroClear and TangoBlackPlus resins for respective rigid and flexible parts.
With added electronics (powered by Raspberry Pi) the team has used TWISTER to make a soft robotic arm capable of gently handling objects such as eggs and fruit. Because of its unique design, the arm absorbs excessive force by flexing in response. The soft materials also mean the now patent-pending design could be added to assembly lines in place of other more rigid, and often enclosed, robotic arms. As Lee explains to CWRU daily “TWISTER is very different from rigid body robots […] Because this robot can be made with soft materials it could be safe to use on an assembly line right next to people.”
To infinity and beyond
TWISTER was first demonstrated by CWRU as a worm-like all terrain robot. Toward the future, the Lee team is looking to use shape memory alloys to realise the TWISTER design.
Shrinking it down to a microscopic scale is another possibility for medical use, and Lee even sees potential for off-world application, “To put anything into space,” she adds “volume and weight are critical, because of the cost of rocket transport. This robot is fully collapsible and, compared to a rigid arm, light and compact.”
The TWISTER project is supported by two papers recently presented at the 2017 NASA/ESA Conference on Adaptive Hardware and Systems (AHS) and the IEEE/RSJ International Conference on Intelligent Robots and Systems. Supporting Lee in the research are Yanzhou Wang, Evan Vander Hoff, Donghwa Jeong and Tao Liu.
Featured image shows Case Western Reserve University’s 3D printed TWISTER arm. Photo by Russell Lee/CWRU
| Monday 17 August, 2015
by Calvin Peat
The late film director Tony Scott, also a painter, said that he viewed the process of directing his films as painting with light. Now, it seems, such an approach to film-making is possible in a far more literal sense. There have been numerous advances in the burgeoning field of 3D printing, and one of the more interesting areas is that of the interplay between 3D printing and light.
One aspect of this is that a 3D printer can be modified such that light itself can effectively be ‘printed’, as the Beijing artist Ekaggrat Singh Kalsi shows.
Inspired by Kalsi’s work, Aron Bothman, a student at CalArts, decided to apply the idea to film-making for his the2sis project, The Red Witch.
Each CGI image from Maya is sent one frame at a time to the printer, thus creating the illusion of movement, in much the same way as stop-motion. An 11-second example of the 3D-printing-with-light technique can be seen here.
He and his father built the printer from a kit, but replacing the hot end with an LED. As 3D Print reports, “This allows Bothman to capture the light on film by using a long exposure while the printer runs the model, tracing out the shapes as a 3D light painting.”
Aron Bothman said, “As a stop-motion filmmaker, 3D printing allows me to tackle more ambitious projects on a short production schedule than I might have been able to otherwise.”
The finished 6-minute sci-fi short film about a geologist on Mars, The Red Witch, combining stop-motion, CGI, and hand-drawn animation, can be viewed here.
There have also been other interesting developments in the area of combining printing and light. Let’s take a quick look at just a handful of examples, in no particular order.
Firstly, in his research involving printing onto polymers or plastic using light, Associate Professor Nicholas Fang at MIT broke the diffraction barrier. Fang said, “We were the first group that proved that we can print sub-wavelength features a hundred times smaller than a human hair.” Implications of this breakthrough include the ability to increase the amount of data that can be written onto a DVD by 100 times, investigate DNA, and potentially even break a CPU’s operating limit of 10^12 Hertz by replacing electrons with optical cables.
Secondly, a company called Rohinni in the States has an LED lighting product called Lightpaper, which they claim is the thinnest in the world. As 3DPrint reports, “While Rohinni does have mild competition in the area [of LED lighting], they do have one completely unique factor: Their product is razor thin. And flexible. And 3D printable.”, adding, “According to Rohinni, the emergence of printable light is on par with 3D printing in terms of new possibilities and application potential.”
Thirdly, the Sci-Arc Gehry Prize in 2012 was won by Kyle & Liz von Hasseln for their project Phantom Geometry, which literally uses light to 3D print solid material. In addition, at any time during the process it can be stopped in order to make adjustments before continuing.
And finally, such creativity in the field of 3D printing is not limited to using light. For instance, there’s a dynamic water sculpture at Osaka Station City in Japan, which effectively does a similar thing as Kalsi and Bothman, but 3D printing using water instead of light.
With such incredible achievements in 3D printing, what’s next? It’s an area with a lot of exciting potential.
Crowd-funded project to provide VR views from International Space Station
3D-printed ‘smart cap’ detects spoiled food
3D ‘smart camera’ landmine detection research wins NGO funding
Self-powered transparent paper promises new wave of ‘smart transparent paper electronics’
HP Sprout 3D system now integrates 3D capture and printing
Image credit: Wikimedia Commons
Unlike most animals, seahorses have tails that are made of square prisms. Scientists are now looking to this small fish with horse-like head and curled tail dwelling in the deep seas for ideas that could lead to better robots and medical devices.
In a new study published in the journal Science, researchers explored the makeup of the seahorse tail and rendered its mechanics using 3D-printed prototypes. They wanted to determine whether the grasping ability and armored functions of the cross-sectional architecture of seahorse tail are better than cylindrical tails.
“Almost all animal tails have circular or oval cross-sections—but not the seahorse’s. We wondered why,” said study lead Michael Porter, an assistant professor in mechanical engineering at Clemson University, in a press release.
Porter had been working on square cross section catheter before trying to building a round one to enable inserting it to the veins. However, the square device worked better than the cylindrical one.
“The square one just felt better. It felt like it basically fit together better and just performed more robustly, whereas the round one just didn’t really hold its shape well and just didn’t seem to fit together as well,” said Porter.
“Michael decided to use engineering and technology to explain biological features,” said study co-author Joanna McKittrick, materials science and engineering professor at the University of California.
The researchers hope to use biology as a source of inspiration for engineering, and engineering as a tool to explore biology.
“New technologies, like 3D-printing, allow us to mimic biological designs, but also build hypothetical models of designs not found in nature,” said Porter “We can then test them against each other to find inspiration for new engineering applications and also explain why biological systems may have evolved.”
Because the square plates make it stiffer, the researchers found that seahorse tail makes for a sturdier armor, and able to resist more strain. In fact, the square model outperformed the cylindrical one in all crushing tests.
Made up of about 36 square-like segments composed of four L-shaped corner plates, seahorse tails easily squeezed inward while maintaining its shape. The plates are able to glide or pivot similar to ball-and-socket joints, making it easier to slide past one another.
The seahorse tail model could also grasp and grip more firmly because its square segments create more contact points with the surface of the object compared to the rounded tail. Although the range of its movement is limited due to the plates interfering with one another, the seahorse tail returned to its original shape using less energy compared to the cylindrical model.
“Understanding the role of mechanics in these prototypes may help engineers to develop future seahorse-inspired technologies that mimic the prehensile and armored functions of the natural appendage for a variety of applications in robotics, defense systems, or biomedicine” the authors wrote.
Study co-author and UC engineering professor Marc Meyers noted, “The possibilities are many.”