The human hand is an amazing machine, and duplicating even a fraction of its abilities in a prosthetic is a daunting task. Flexible anthropomorphic prosthetics can reach tens of thousands of dollars and are beyond the means of many of the people who need them. So imagine the impact a $200USD prosthetic hand could have.
For such a low, low price you might expect a simple hook or pincer grip hand, but the OpenBionics initiative designed their hand from the outset to mimic the human hand as much as possible. The fingers are Plexiglas with silicone knuckles that are flexed by tendon cables running in sheaths and extended by energy stored in elastomeric material running along their dorsal aspects. Each finger can be selectively locked in place using a differential based on the whiffletree mechanism, resulting in 16 combinations of finger positions with only a single motor. Combined with 9 unique thumb positions, 144 unique grasp are possible with the open source hand built from hardware store and 3D printed parts. Stay tuned for a video of the hand in action after the break.
3D printing is beginning to prove it’s the next big thing in prosthetics. Hackers are coming up with all kinds of static artificial hands, from the elegant to super-hero themed. Maybe the mechanism that OpenBionics has come up with will find its way into these hands – after all, it is an open source project.