Soft Robots

Print Your Own Robot: Part 3 VIDEO!

| Matthew Borgatti

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.

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Print Your Own Robot: Part 2

| Matthew Borgatti

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.

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Print Your Own Robot: Part 1

| Matthew Borgatti

I’ve had an outrageous streak of luck, lately. Firstly, I got a lovely plug from BoingBong (via the additionally lovely Xeni Jardin) that introduced a whole slew of new people to my store. Secondly, an event I’ve been hosting over at my shop, Craft Night, has been drawing an incredible crowd of excellent makers. It’s starting to feel like I’ve got a genuine tribe here in the city. Thirdly, I’ve finally been able to experiment with a technology I’ve been talking about and sketching for years: soft robots.

My friend, the extraordinary jeweler, maker, and programmer Aaron Waychoff, introduced me to Jim Bredt. Jim is many things. He moonlights as the human spotlight at the Ignobel Awards. He’s a metal smithing, mold making, 3d printing, material scientist, MIT professor. He also won an award for being a major ball buster when he taught “Introduction to Solid State Chemistry”.

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