Simon is a self-proclaimed “tinkerer” who volunteers for e-NABLE, which provides inexpensive assistive technologies to underserved communities.
With a 3-D printer and $50 worth of materials, Simon made Delgado a hand that Delgado says makes his life easier, especially at work, where he often lifts and moves boxes.
The 3-D printed hand, a model known as the Cyborg Beast, gives him 10 movable, functional fingers, whereas the old hand, which looked more real, only allowed him to grip things with two fingers and a thumb, Delgado said in a video interview posted on YouTube.
Delgado also said driving and carrying bags is easier with his new hand. Another bonus is that if the hand breaks, it can be replaced cheaply.
“This is obviously not an ‘apples to apples’ comparison in terms of the devices but the real value of a prosthesis comes from how useful it is on a day-to-day basis,” Simon wrote in a YouTube post.
Simon’s YouTube post explains how the hand works:
There are a series of non-flexible cords running along the underside of each finger, connecting to a “tensioning block” on the top rear of the device (the “gauntlet”). The tension is caused by bending the wrist downward. With the wrist in its natural resting position, the fingers are extended, with a natural inward curve. When the wrist is bent 20-30 degrees downward, the non-flexible cords are pulled, causing the fingers and thumb to bend inwards. A second series of flexible cords run along the tops of the fingers, causing the fingers to return automatically when tension is released.
The experiment is ongoing. Simon plans to print another hand for Delgado using Bridge nylon, which is stronger than the ABS plastic (the stuff Legos are made of) used in the first hand but still lightweight. Simon and Delgado will also try a new thumb that allows for a different grip.
“I believe that 3D printing is a transformational technology. Jose’s experience is a great example of that,” Simon wrote on his blog.
You can find links to the model Simon used for the hand along with instructional videos on his blog.