An educational soft robot

[PetterWehlin]

Hello everybody,

We made a soft robot!


We call it SoftMod and it is a modular soft robotic system. It was created by three undergraduate Mechanical Engineering students; Petter Wehlin (me), Bryan Duerfeldt, and Isaiah Genece, at Yale University during the fall semester of 2016.

The project was developed as part of the class Mechanical Design: Process and Implementation (MENG 489). The prompt from the instructors to the students was: “Create a classroom kit that can improve the current state of mechatronics education.” In response to this prompt we created a vision about a kit that was innovative, unlike any existing kit on the market, and that gave the students a lot of design flexibility.

With this vision in mind we decided to make a modular soft robotics system. The system was going to consist of several soft pneumatic actuators that could attach to themselves and to a base in a nearly infinite number of possible configurations. We also wanted to include all the necessary pneumatic and electronic components needed to power and control the soft actuators, in order to create a complete mechatronics “lesson plan” for a potential university level class.

The final design consisted of two fiber reinforced soft actuators, a base to attach them to, a pneumatic circuit (access to pressurized air is assumed), and electronics (including an Arduino microcontroller). Our system is not specialized for any specific application, but has rather been developed to be customizable for any application of choice, encouraging potential students to take ownership of their own projects.

I have also posted a manual with more technical depth here: https://yale.box.com/v/softmodtechnicalmanual
Other supporting files can be found here: https://yale.box.com/v/softmod
And here are three videos of it in action:
https://www.youtube.com/watch?v=K20oZ_aAuSg
https://www.youtube.com/watch?v=5CZPDOBrQf8
https://www.youtube.com/watch?v=EEhAm3DWMc0

I'd love to hear your thoughts on this!

- Petter

[XYZAidan]

Hi Petter,

This is fantastic work! Compliments to the whole SoftMod team for creating this. There is a lot about this project that is really fascinating and cool. I'm quite fond of the idea of modular soft robotics, and I think the platform you've developed for controlling and testing soft pneumatic actuators is a great step in that direction. I also really like the idea of modular connectors for implementing actuators in series. The use of soft sensors like FSRs in you actuators is also very well done. Adding sensors to compliant control systems opens up many possibilities (as can be seen in your third video).

It seems you've done some very thorough testing of your system. I'm quite interested in your investigation into how PWM frequency effects minuscule motions in actuation. I feel problems and research topics such as that are often (wrongfully) overlooked, so it is wonderful that you're looking into this!

The conclusions you've drawn from your research and development are very valuable. It's interesting that you find that Finite Element Analysis is not super-useful. In my own research I've barely ever utilized simulation, as I find design intuition and rapid prototyping to be a more useful strategy. I think that overall your suggested curriculum for the SoftMod is a great plan that weaves together a lot of meaningful interdisciplinary knowledge.

As I said before, amazing work! You should be very proud of your project. I'll make sure the scientists of Super-Releaser see this, so expect a response from them as well.

Aidan Leitch
Super-Releaser Intern

[Ikyotochan]

Nice work, particularly on the documentation to make your work repeatable. I think it really delivers pretty well on the intention of being feasible to be implemented in the undergraduate level classroom. Information about soft materials and systems FEA tends to be of great interest to the larger soft robotics community, so going into more detail on your team's process in that area would add to the conversation.

[ugabuga]

The video shows a good solution if you have already cast your actuator, however I recommend you include the "adapter" as part of your design and cast as a part of the actuator.

Also I would also print an adapter which flares out and can slip around the air tube and get glued there. this way even before adding the zip tieyou will have something holding the tube in place.