For one Industrial Design student residing in the United Kingdom, named Fraser Leid, 3D printing has provided him with a means of reinventing the prosthetic hand.
“I try my utmost to go against the status quo by innovating anything and everything that comes to my mind,” Leid tells 3DPrint.com. “It requires a lot of thinking, and a lot of the time. It involves questioning ‘why’ things are made the way they are.”
One project which really piqued our interest was one that he calls “Prehensile.” It is a design for a 3D printable prosthetic hand unlike anything else we have ever seen.
“The Inspiration behind the Printed Prehensile was the idea that it came in a kit — something that a person without the limb would be able to buy and have assembled — which in turn, would greatly lessen the cost of the prosthesis and also allow the user the opportunity to personalise it (Hands building Hands),” Leid tells us. “The system is a blend of various thicknesses of ABS Plastic and Aluminum fittings, which either are assembled with cap screws or as a snap-fit. An interesting take on the idea was to integrate Nylon cord as the material required for flexor and extensor movements, as well as individual coiled springs to help the fingers to reset.”
The fingertips on the Prehensile are rubberized in order to allow for easy gripping and placement of objects. These fingertips are assembled onto the hand in such a manner that they can easily be replaced once they wear down. As you can see in the photos provided, the hand is quite elegant looking, and Leid was sure to construct so that it closely mimics the mechanics of a real human hand. The goal wasn’t simply to create a prosthetic hand that would be “normal looking,” but instead it was to create a device which would be attractive.
It emulates the 27 bones in the human hand, consisting of various thicknesses of aluminum tubing and coiled springs. It then uses nylon to cords (two per finger) to allow for the flexing and/or extension of each finger.
The Prehensile hand consists of two main sectors:
- The Phalanges Collective – This is the array of digits from the fingertip to the knuckle joint.
- The Metacarpal Housing – This is the hand’s center of operation, which houses the nylon flexor and extensor units.
The 3D printed ABS plastic components are easily printed and then assembled together either as snap-fit parts onto various joints, or fastened down with stainless steel screws. For those individuals ordering kits, they would receive the metal parts as well as STL files for 3D printing. All they have to do is print the parts, based on the size they need, and then assemble the hand.
“Something all the more important that I wanted to address, and probably most important of all, was to make the internal mechanics visible because I believe that anatomy of this nature is elegant to witness (Like a skeletonized watch),” Leid tells us. “I wanted the wearer to be proud of their prosthesis, not shying away because they have a disability, but to even go so far as to boast about it and to show people how it works. From the feedback I’ve received so far, many are drawn to it because of its presentation. It seems like people enjoy the things that are a little bit out of the ordinary. “
Currently the Prehensile hand is still in the “prototype phase,” but Leid hopes to have a more refined version ready to 3D print within a year. It will certainly be interesting to follow the evolution of this hand as Leid progresses the design further.
What do you think about this elegantly designed 3D printed prosthetic hand? Discuss in the Prehensile Hand forum thread on 3DPB.com.
