October 28, 2013 AT 4:00 pm

Provocative Ideas from the *FINAL* October 25th “Make the World: Prosthetics” Hangout! #maketheworld

Phil Torrone, Limor Fried, and Matt Griffin from Adafruit were joined by Michael Curry, 3D Printing Evangelist from MakerBot, in the Adafruit Headquarters to host a lively one hour wrap-up to the #maketheworld: Prosthetics series!

A Brief Recap

  • Easton LaChappelle, 17yo, currently working with Anthromod and at NASA on the Robonaut project. He told his story, getting started at fourteen making robotic arms, and how he became taken with the goal of making affordable robotic prosthetics. He also demonstrated how his hands work, moving the fingers independently!
  • Gael Langevin fron Paris, France, creator of InMoov, talked about the history of creating the InMoov open source, 3D printed robot on his desktop 3D printer, and shared a tech demo of his InMoov robot performing.
  • Jon Schull, Rochester, New York. Teaches a course in Innovation and Invention in RIT’s School of Interactive Games and Media at RIT. He is a key community leader and participant in the e-NABLE G+ Community where they are “trying to create a crowdsource network of distribution of assistive technologies on an infrastructure of the Internet and goodwill.” He shared some photos from Andreas Bastian featuring some exciting experiments with PLA gauntlets.
  • Jorge Zuniga, Omaha, Nebraska, professor at Creighton University is an e-NABLE participant as well. (Originally from Chile.) Has been exploring how to make Robohands easier to produce and cheaper.
  • Matt Stultz, founder of 3D Printing Providence, along with many key members, hosted a Prosthetics Build Party for 3D printing enthusiasts, calling all members to join together to put their printers to good use. And the party was happening — they had “as many 3D printers as table space.” They gathered together to print a large number of Prosthetic hands that are to be sent with another team to Africa for children in need.

A few challenges for the community to continue to explore!

Challenges for Robotic Prosthetics

  • How do you control the arm?
    • InMoov initially used longer cables to control processes to eliminate motors from light portions of the arm, but the cables stretch over time.
  • How do you route this information back to the user?
    • Easton: “The biggest challenge is interfacing with a human body.”
  • What sort of sensors can be used to help simulate the sensation of touch and grip feedback? Establish distance/proximity?
    • Limor advises against sound-based proximity sensors for working with close objects, and suggests instead light-based sensors, which do a better job up close.
    • Easton tends to use Force/flex sensors, which mimic more specifically how humans handle information when handling an object.
    • He has also experimented with surface transducers to use sounds as a means to “transmit experience of touch, texture and sound” back to the user.

Challenges for Construction

  • Weight of prosthetics is a big deal for endusers.
    • Easton received feedback from users about the importance of minimal weight for a prosthetic device. “The human arm is about nine pounds, and I have been aiming to make robotic arms that are closer to six pounds.” His current model is said to be able to lift 150 pounds and move from 0º to 90º in about six seconds — quite an achievement for so light a robotic arm!
    • Gael didn’t originally create his piece to be a prosthetics (only lifts about 1 kilo), much better as an experiment to learn about robotics and interaction. He is working to design a new project that is designed to be a prosthetic.
    • Matt Stultz and the 3DPPVD team have been experimenting with printing the robohand in nylon, tremendously strong, but also flexible and self-lubricating.
  • Tuning the design (and sheath) for better comfort for the users
    • Experimenting with alternatives to Orthoplast and other expensive, orthotic-related medical materials
    • Andreas Bastian in the e-NABLE community has been experimenting with using heat to re-mold PLA printed prosthetics as handy alternative to creating sheaths.
    • Andreas has also tested mesh patterns to help control the deformation of the material and offer a range of rigidity.
    • Jorge showed a design that uses velcro sheath material to make it easier to custom-fit a recipient far away who can’t be fitted directly.
    • Chemicals exist that can “rubberize” or coat printed materials can further modify the rigidity of elements of a printed piece or make it more human skin friendly.

Challenge to reach those who need affordable DIY prosthetics

  • Jon shared about his excitement seeing the design collaboration happening in the online community around 3DP open prosthetics.
  • Key next step is moving from designing cool technology to getting much better information back from the users about what they want and need.
  • e-NABLE has had a few hangouts and may meet together physically to continue this conversation.

A few future challenges:

  • We need better solutions to help with long-distance fittings.
  • We need to tune how the models are plated for faster production without sacrificing material strength.
  • We need to offer more specific finger-by-finger, joint-by-joint control and feedback to offer a larger range of use and sensation

Where to Getting involved.

  • Join the Adafruit Community and e-NABLE to continue these conversations.
  • The InMoov project, with files shared on Thingiverse, has been taken up by makers all over the world. A number have been modified for various purposes or to add new functionality.
  • Easton, Gael, Robohands, Joel from OpenHands, and other designers all shared and learned from each other by sharing their files online and collaborating in that space.
  • In addition to continuing to experiment with materials, the 3DPPVD team will be continuing to print open prosthetics during their meetings every second wednesday of the month and at print parties like at AS220 in Providence, RI.

Thank you again for all of your efforts so far for this great cause!


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