The 3D-Printed Prosthetic Hand

By Humans Invent on at

When carpenter Richard Van As cut off four of his fingers on his right hand in a circular saw accident in 2011 he was presented with a problem: how to continue his work as a carpenter without bankrupting himself on a prohibitively expensive prosthetic hand?

Van As tells Humans Invent, "I had two problems. One, finding something that's functional for a tradesman for instance, and second, something that was within the reach of normal people -- prosthetic limbs are ridiculously expensive."

While still in hospital he resolved to build his own replacement fingers that would not break the bank, but even he could not have predicted the revolution in low-cost prosthetics that his early prototypes would set in motion.


Printed Hand

One successful round of funding on Indiegogo and two years of experimentation later, Robohand is the fruit of his labours: a replacement hand that can be printed, assembled and fitted anywhere in the world at a tiny fraction of the cost of its myoelectric counterpart.

When Makerbot, a trailblazing producer of 3D printers, donated two printers to Van As, prototyping of the radical new open-source project became fast-tracked, and Robohand was born.

The first person to benefit from a new Robohand, made mainly from plastic, was a five year old boy called Liam with amniotic band syndrome in Richard's native South Africa.

Liam's ABS meant that he had very little in the way of fingers but crucially could bend his wrist, and based on this motion Richard was able to build him a hand capable of grasping.

"I don't consider myself a major genius or anything," says Richard, "I basically just copied what was inside my hand, and moved it to the outside. The only thing you can't mimic is a tendon, because a tendon can push and pull and what I did was I had to then have a bungee to return the finger and then a cable to pull it."


Open Source

The design files of the new hand were uploaded to the open source 3D-printed design sharing network Thingiverse, where the parts needed to assemble a Robohand have exceeded 14,000 downloads to date, while Richard set about raising $10,000 on Indiegogo to fund the production of hands that he would personally fit for children with ABS.

"Me personally, I've done well over a hundred hands," says Van As. "But money only goes so far. Most of the people who are being helped don't have funds."

As each person adapts to their Robohand, the range of things they are able to achieve varies greatly.

"Person to person they tend to surprise me," says Van As. "Some guys can do this, some guys can do that: one of them can hold a pen and write with it, some of the kids can't, but they learn. One of the kids, a 13 year old boy, can catch a cricket ball coming off a bat, and he plays under 14's cricket, so he was accepted into his team."

Richard is currently in the process of setting up a non-profit organisation to make it easier to accept funds to build new hands, but what if money wasn't a factor? -- "I'd be mass producing it, in all different sizes," says Van As.

"What I'm trying to do is put together a Robohand world tour. There are guys all over the world who are interested in being taught how to do this, and hopefully the idea is you teach one, and then the next one gets taught, and further, and it will spread by itself."


Changing Lives

Of all the ambitious projects made possible by 3D printing, the difference made to the lives of children by Robohand is one of the most inspiring applications of this technology.

"When they go to school they're like the coolest kids in the school. Kids can be cruel, and they were teased before because they had a shortcoming in the hand, and now that they've got this Robohand thing, they're like the best thing, everybody wants to be their mate now," says Van As.

"There's a child in the U.S. with a myoelectric hand that cost $57,000, and the child won't wear it because there are braces and harnesses, you can't get it wet. How many hands could I have done for $57,000?" he adds. The costs can vary, but the answer to this question is somewhere around the 100 mark, with prices dropping even further if you print and assemble Robohand yourself.

As Richard waits for his approval as a non-profit organisation, and the designs continue to be shared on the internet, the question begs to be asked: just how many people can Richard literally give a helping hand?

Robohand has been nominated for the Rockefella Innovators award and Van As has been asked to create a display in the Science Museum, London. To pledge money head to Robohand.

 Humans Invent is an online space dedicated to celebrating innovation, craftsmanship and design fuelled by our most natural instinct – the pursuit of invention to help solve a human need. You can read their original article here.