A man with dark skin in a red shirt and khaki shorts sits in a chair. His left leg has a prosthetic below the knee. The upper half of the prosthethic is an off white plastic socket with flecks of different off white plastic throughout hinting at the recycled nature of the plastic. The lower half is a metal tube attached to an artificial foot in black sandals.

Precious Plastic Prosthetics

February 20, 2023 by Navarre Bartz 8 Comments

Plastic waste is a major problem, but what if you could turn the world’s trash into treasure? [Yayasan Kaki Kita Sukasada (YKKS)] in Indonesia is doing this by using recycled plastic to make prosthetic legs.

Polypropylene source material is shredded and formed into a sheet which is molded into the required shape for the socket. A layer of cloth and foam is used to cushion the interface between the patient and the socket itself. Using waste plastic to make parts for the prosthetics lowers the price for patients as well as helps to keep this material out of the landfill.

What makes this project really exciting is that [YKKS] employs disabled people who develop the prosthetics and also trains patients on how to maintain and repair their prosthetics with easily sourced tools and materials. With some medical device companies abandoning their devices, this is certainly a welcome difference.

We’ve previously covered the Precious Plastic machines used to make the plastic sheets and the organization’s developments at small scale injection molding.

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Hackaday Prize Entry: Robotic Prosthetic Leg Is Open Source And 3D-Printable

May 25, 2016 by Moritz Walter 19 Comments

We’ve been 3D-printing parts for self-replicating machines before, but we’ve been working on the wrong machines. Software and robotics engineer [David Sanchez Falero] is about to set it right with his Hackaday Prize entry, a 3D-printable, open source, robotic prosthetic leg for humans.

[David] could not find a suitable, 3D-printable and customizable prosthetic leg out there, and given the high price of commercial ones he started his own prosthesis project named Drakkar. The “bones” of his design are made of M8 steel threaded rods, which help to keep the cost low, but are also highly available all over the world. The knee is actively bent by a DC-motor and, according to the source code, a potentiometer reads back the position of the knee to a PID loop.

While working on his first prototype, [David] quickly found that replicating the shape and complex mechanics of a human foot would be too fragile when replicated from 3D-printed parts. Instead, he looked at how goat hooves managed to adapt to uneven terrain with only two larger toes. All results and learnings then went into a second version, which now also adapts to the user’s height. The design, which has been done entirely in FreeCAD, indeed looks promising and might one day compete with the high-priced commercial prosthesis.