Building A Prosthetic Leg From Scratch

[Radek] from Poland sent in a neat video of a bionic prosthetic leg he made for one of his patients. Even though [Radek] says it’s a ‘prototype of a prototype,’ we’d have to agree with him that it’s a very neat build that could provide inexpensive motorized prosthetic legs to amputees in the future.

[Radek] has been working on his project for about two years now, after building the motor and electronics by hand. The leg is powered by 1.5 kilogram battery pack – no details on the chemistry of the batteries, but [Radek] says it will last 12 hours on one charge. There are also small vibration sensors in the leg for a bit of feedback, and a few switches so the knee joint can be operated by the stump.

If you’re wondering where [Radek] got the proper tools and materials to make a carbon fiber prosthesis, he works for Carbon Prosthetics where builds simple prosthetic devices. His bionic leg creation looks really cool, and he says the final product will be much less expensive than the very high-end bionic prosthetic legs.

[Radek] was kind enough to share some more videos and a few pictures of his robotic prosthetic leg; you can check those out after the break.





18 thoughts on “Building A Prosthetic Leg From Scratch

  1. Darth Vader’s right leg. :-)

    The movement for climbing stairs still needs a little more tweaking.
    It appears to have insufficient backward movement to clear the steps.

  2. Haha how timely, I was hitting on a girl last night with a prosthetic.

    I thought it was going wildly well, she was putting up with my hands ever more brazen advances up her thigh.

      1. whoops didn’t actually finish the story, my hand ever higher until it hit real skin and she leap out of her seat and screamed. Then I screamed and then scuttled off.

  3. While it’d far out,but respectfully I’m not sure why we are to be amazed. The prosthetic was made by a company whose goal is to make prosthetics. The prosthetic has a serious case of drop foot as seen on the stair climbing video. My guess is the exerciser machine was used to help th patient learn to control the prosthetic. To be honest I find the prosthetic making efforts of family or fried feature at instructables more interesting True their efforts create old school prosthetics, butt hey are serving the patient when/where there are no alternatives.

  4. I agree – nothing to be amazed.
    But first -there is a one of realy first test
    secondary – prosthetic company is for not create new prosthesis -its for sold other parts aviable
    i dont have budget like Darpa or Ossur , i must create almost all from hand…
    This is reason to create This prosthesis..
    You must wait for more :)

  5. Good work I guess, but I never understood why prosthetics are as shitty and expensive as they are.

    I mean, there are instructables on how to build EMG-sensors and interface them with common microcontrollers. There are instrucables for building your own flexible and strong “air hose”-muscles. There is even a plethora of information on sensory substitution, a ludicrously simple and inexpensive way of getting natural sensation from the prosthetic device.

    A carbon fiber frame, air hose muscles in the front and the back of the thigh with pressure being directly controlled by the amount of muscle contraction in the muscles of the stump, and things like pressure sensors in the sole of the foot controlling vibrators (“tactors”) on the wearers skin. Unlike motorized prosthetics, something using the pneumatic hose muscles would be able to move slowly and deliberately or fast and with power just like an ordinary muscle.

  6. I came up with an idea for a variant of this based on liquid metal alloys and aligned galfenol fibres.
    The idea is that you inductively or electrically heat the LM alloy to its liquidus point, then apply magnetic field to make the galfenol change shape.
    If you drop the alloy below its liquidus point the muscle “locks” in place without damaging anything.

    Another variant uses standard (cheap) muscle wire but the liquid metal acts as a support and structural reinforcing mechanism with the previously mentioned locking effect.
    Here, changing temperature makes the wire contract with pairs of opposing muscles to offset each other.

    Anyone interested? mailto mandoline at cwgsy dot net with the hashtag #twitch

  7. Also, another fascinating idea is to scratch build LVDT’s using home wound multilayer coils.
    These are also relatively easy to make, and using about 30 hair thin wires in a circular braid wound on the former like a Tesla coil secondary would allow it to carry significant current.
    Add multiple layers of turns with the ends in phase, then make a second coil with single turns as the “rotor” feeding that from DC power to avoid using expensive magnets.

    Plus if something goes wrong the remaining wires can carry the current just fine.

    1. So amazing I have waited for 3 yrs for a leg tjat fits I have a standard leg that is gonestly dangerous to wear. I lost my leg above the knee due to an accident. Well done slightly jealous i wish i could do something like tjis

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