I’ve been playing with origami, lately. Specifically, I’ve been exploring how to simulate, model, and fold origami shapes in ways that could be automated to create useful mechanisms. The system I’ve come up with is designed to fold rip-stop nylon, which I’ve worked with a bit during my time at Makani Power and research at Super-Releaser.
After some experiments with programs designed specifically for generating origami patterns, I found I wasn’t able replicate the patterns I’d prototyped in paper. Since I wanted to start out with a paper prototype, do some bench tests, and move to CAD from there, I needed to consider other options. I also wasn’t able to convert the output into a format that would play with CAD for printing and prototyping the resulting forms. So, I fell back on my old standard: SolidWorks. If you’ve worked with me before or you’re a regular reader, you don’t get any bonus points for guessing I’d find a way to turn this into a SolidWorks project. This video was very helpful for understanding how to think about origami in a SW context.
A few months back I reprised my role as robotics mercenary and general fixer, spending a week working on David Nunez’s Requiem for Rhinos installation at Illuminus Boston. David is a researcher with Todd Machover’s Opera of the Future group at the MIT Media Lab. The idea at the core of the sculpture is the passing of Nabire, one of the last northern white rhinos in existence. Only four remain and they are so closely related that rekindling the species is impossible. The sculpture was conceived as a grand send-off, with Nabire’s kin descending from the ceiling to wish her on her way.
I was hired by SOLS to help out with their Adaptiv project. The idea was to showcase the procedural modeling techniques, materials, and technologies behind their printed insoles with a futuristic robotic shoe. Jordan Dialto, the industrial design lead at SOLS, approached me in my capacity as lead scientist at Super-Releaser to make a prototype soft robot shoe that could change shape and fit in response to the wearer.
The project started out with an external shell modeled by Continuum Fashion. Although the design was elegant, this posed a challenge for introducing the robotic elements and the engineered components that would stitch everything together. Since the external shell was generated in a mesh CAD program, it didn’t fit into SolidWorks’ reference frame. This meant using the mesh as a reference and generating a simplified surface to extrude the soft robot elements and retaining skeleton from. Continue reading →
Last week I headed up to Viridis3d for some more hacking. We got some beautiful results using some vaccuum casting with the trefoil design, parts printed for both the internals and outer shell of the quadruped, and schemes for tempting new mechanisms. All in all it’s been really exciting seeing the progress. Also, I have some updates on controlling the trefoil tentacle with an arduino powered set of air solenoids.
One of the confounding factors in getting this flavor of robot moving predictably has been how difficult it is to control wall thickness and bubble inclusions when casting the final silicone pieces. Like almost every mold, you do the best you can, try to create a nice, sterile, well ordered universe, and hope. Although Dragon Skin has performed really well as a durable, flexible silicone, it has the nasty habit of trapping bubbles in inconvenient spots when curing. Many silicones have a thin, pancake syrup consistency when mixed, but Dragon Skin is much more like honey or molasses, meaning it’s really easy to trap bubbles in the mix while stirring and have them set in place when everything’s curing. A good solution for the problem is pulling them back out with a vacuum chamber. Continue reading →
I’ve finally gathered my wits after a whirlwind tour of Europe, starting at CCC, giving some talks and connecting up with potential collaborators, to Berlin to meet hackers I hadn’t seen in years, to Brussels to play with some material science experiments in impact resisting plastics. While at CCC I gave three talks, two lightning talks on digital fabrication and the strange world of news advertisement, and a 15 minute talk on the methodology and philosophy behind my soft robots. I’ll be uploading the short talks sometime soon, but for now please see my soft robots lecture after the jump. Continue reading →
I have lots of updates to share. First, there’s a new video of the latest tentacle prototype in action below the fold. Second, We’ve made some excellent progress on the method of manufacture, reliability, and repeatability of the designs we’re producing. It’s almost at the point where we need to figure out a good real-world experiment to test our ideas against. I’m currently torn between creating a grasper and something that walks. Jim and I have been working out ways of getting a self contained power source inside of a soft robot, and it seems like we might be able to use a canister of compressed gas to do everything from timing movements to articulating valves. I’m working out ways of integrating peristaltic pumps and timing mechanisms that will be simple to prototype… which is a pretty tall order. However, I think a combo of laser cut bits and creative molding can have this one solved. Continue reading →
After only six actual work days, a few afternoons spent on CAD, and a lot of tweaking, I’ve got a working robotic tentacle prototype! I used the hand pump off of a sphygmomanometer and a lot of sil-poxy, but it’s working in a rough and ready way. There’s video after the jump below.
I had to cut this one open to fully remove all the core and then sealed it back up. I think the next version will evacuate the core cleanly due to the powder tweaks we made, though. It could also use some revisions to the way it interfaces with the air supply. In the future I’m going to have to run some tests on adhering silicone to various plastics to see what will make for the most solid fittings. The sil-poxy infosheet says polyurethanes are a good candidate, so I might start there. Continue reading →
I just arrived back from a second session of hacking and casting with Jim Bredt over at Viridis3D, and I have to say I’m pretty excited. The biggest result of the most recent round of mold making is a successful method for getting soluble cores into printed molds and casting silicone around them reliably and repeatably. I ended up doing a lot of revisions to the casting method and industrial design based on the results of last month’s experiments. The mold goes together in new ways with changes to accommodate pouring the mold, reusing the outer shell, aligning the cores, printing the cores, and how it will get hooked up to pneumatics once everything’s cast and functioning. I’m especially proud of the design behind the base of the soluble core, which is tapered so that it can align and center itself within the mold even if its dimensions shrink by a few percent. The little ears on this base are both to align it rotationally (which doesn’t matter much as far as the tentacle is concerned, but could matter in other more complex molds) and to prevent the core dropping down further into the mold and mucking up the wall thickness if it shrinks more than spec. Continue reading →
One of the deep and subtle magics of fabrication is how many ways you can get approximately the same result with different procedures. It’s a bit like cooking, where the choice of whether to bake or broil, pan fry or deep fry, can have a profound effect or make little difference at all depending on what goes in and the desired result. Having a laser on hand means I can fiddle with my methods and iterate a bunch of different solutions each with minor tweaks until I get the result I was searching for. Also, with the coming laser singularity (when lasers become more common than printers), more materials and toys are available for added lazing satisfaction.
I started off with a late night doodle. My favorite Chinese Take-Out place has this excellent illustration. The gun was my own addition, on top of a wonky and not quite convincing “thumbs up”. I though making a stamp following that design, obtaining a stack of menus, improving them, and shuffling them back into the main cache over at Randy’s would be amusing, so I set about making a stamp.
The first step was to get a copy of the unaltered menu, photograph it flat, and get the proper dimensions for the stamp into Illustrator. Often times I’ll put things in a scanner to make sure everything’s flat and orthographic, but laying a ruler against what you’re duplicating and photographing it from straight above also works well. Continue reading →