Print Your Own Robot: Part 7

Print Your Own Robot: Part 7

I am now the grinning overlord of a fully functional robotic tentacle. I’m quite pleased. After a few iterations, some hair pulling, and some utterly excellent help from programmer, hacker, and generally awesome person TQ, the Trefoil Tentacle is now waving about in all its eerie undulating glory. You can find a whole set of high res images of it here.

If you're craving an animated GIF of a tentacle wiggling about, this here's your image.

The control scheme is pretty simple: a barebones visual interface in Processing sends signals to an Arduino. From there, it switches the low power signal to high power via a Darlington transistor. The transistor switches each of 3 solenoid valves on and off, providing air to each of the 3 bladders inside of the silicone tentacle. The valves operate on a really slow PWM, their duty cycle determining how much air makes it to each bladder. Since there’s a bleed I can control on the system, I don’t have to worry about pumping air both in and out. I just adjust how much time the valves spend on, and the tentacle does it’s routine. All of the code for the setup is here on Adafruit’s forum.

I got some video of the thing waving about, flexing, and doing a 360 yesterday:

There’s a quadruped design getting its internals injection cast in wax this week, and should be seeing some progress in the very near future. I’ve been making steady progress on setting up an automated system to work out the internal geometry of these mechanisms with Meredith Patterson, and am hoping to have something to show for it in a month’s time. All in all, the world of soft robotics is looking pretty excellent at the moment.

I'm Matthew Borgatti. Howdy.I'm Matthew Borgatti. I run a store called Sleek and Destroy, and I love to make stuff.


  1. An air-powered robotic tentacle using Processing and Arduino « Ponoko – Blog
    Feb 11, 2013 @ 11:04:21

    [...] Borgatti of HAR.MS made this slightly disconcerting yet undeniably fascinating prototype of an air-powered robotic tentacle. The tentacle itself is made of silicon, and an Arudino and [...]


  2. This Open-Source, Robotic Tentacle Will Haunt Your Dreams | TechCrunch
    Feb 11, 2013 @ 16:59:59

    [...] 2) don’t talk about underground tentacle-making. Both of those rules have been shattered by Matthew Borgatti, a robotics designer who has created a life-like, 3D-printed tentacle that flails around quite [...]


  3. MAKE | 3D Printed Soft Robot Tentacle
    Feb 11, 2013 @ 21:29:37

    [...] Matthew Borgatti, whose pop-up, MIDI-controlled Anywhere Organ made an appearance at the 2011 World Maker Faire in NYC, has also been pursuing 3D-printed tentacle-bots for some time now. His most recent iteration was recently completed and you can see it in action, below. Further details of the project can be found here. [...]


  4. 最新のロボット触手は夢に出てきそうな気味の悪さ
    Feb 11, 2013 @ 21:51:55

    [...] 地下室で密かにロボット触手を製造している科学者たちには掟がある。ロボット触手のことは語ってはならない。ところがこの掟が破られてしまった。Matthew Borgattiなるロボット・デザイナーが3Dプリンターから出てきたような本物そっくりの触手を開発し、ビデオを公開した。このロボット触手はArduinoボードを搭載し、ミニ・エアコンプレッサーを動力として悪夢のように不気味にうねる。 [...]


  5. pano
    Oct 04, 2013 @ 08:07:49

    Is there any way that you can provide me a link to the compressor and solenoids you used in this project? i wan to check their specs for a different application.

    really neat by the way and I really like your site.


    • Matt
      Oct 07, 2013 @ 17:03:34

      Thanks for the kind words. Just about any solenoid air valves and compressor will work. The parts I used were just random bits I had lying around the shop. The compressor is a 40psi airbrush pump and the valves are off of a Pneutronics board I found on eBay.

      If you want more details on the process you can find an in-depth tutorial here –


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