I’ve been working with several groups and nonprofits over the last year or two to develop and distribute low-cost prosthetics, especially to refugees and war zones. While some of my designs have made it to some of the Freedom Flotillas, my work is still in the prototyping and testing phase. I hope to get this tested and delivered to as many people as possible and as soon as possible. We are in the process of open-sourcing this on GitHub, and I will add a more complete write-up when published. Please reach out to me if you would like to help in any way!
Organizations I’ve worked with:
Universal Limbs
universallimbs.com
Beyond Motion
https://beyondmotionhub.com/
E-Nable
https://enablingthefuture.org/
Freedom Flotilla Coalition
https://freedomflotilla.org/
Some of my work (an articulated hand design) has been featured on a CBC broadcast that aired earlier this year
Freedom Flotilla
Terminal Device (Hand)
I’m focusing on a terminal device (hand) now, but am also working on mechanisms that provide for wrist rotation and quick disconnects.
I’m exploring manufacturing techniques, including multimaterial 3D printing, silicon molding, vacuum forming, injection molding, laser cutting, CNC subtractive manufacturing, and using carbon fiber and epoxy composites.
Composite Semi-Rigid Design
One version of the hand uses semi-rigid internal structures that function as bones with silicon overmolding to provide a compliant, lightweight, and strong structure that is biocompatible, easy to wash and maintain, and resilient to bumps, drops, and other damage that’s normal in day-to-day use.
Fingers & Palm
Flexible Skin
Multimaterial FDM Printing & Resin Printing
I’ve tried a lot of different ideas for the flexible portion.
- Printing the skin separately using flexible filaments like TPU, TPE, and PEBA, and installing the skin onto the skeleton after both are printed separately.
- Using multimaterial prints to print the semi-rigid skeleton as well as the flexible skin on the same print
- Silicon overmolding on the already printed semi-rigid skeleton
Silicon Overmolding
I’m developing a soft gripping surface for the terminal device that covers at least the palm and finger-tips. I’ve tried multimaterial fdm printing techniques and various soft-resin printing materials and have yet to find a satisfactory solution. I am currently working on silicon molding in conjunction with FDM printing to produce a soft-grip surface to the terminal device. I’ve developed a series of molds for the palm and finger tips and continue to work on this effort.
Goals of the soft gripping system:
- To supply compliance to improve grip and impact resistance
- Provide for a replaceable wear surface
- Use a biocompatible, hypoallergenic material that’s safe for prolonged contact with human skin
Rotation Device
I’m working on a manual hand-rotation device to allow the user to pronate/supinate the hand and lock it into position using their other hand. The device needs to be robust, easy to operate, and allow the pass-through of control cables. I’ve gone through several designs and am still trying to perfect one.
Sketches & Concept Art
Some of the sketches and ideas along the way.
