In the recent years, the traditional idea of secretive design formulas have started to give way to open source, allowing people access to designs and improving communication between developers and users.  Luckily for those with hand and wrist disabilities and amputations, welcoming adopters of open source designs have been 3D printed hand developers.  And while the problem of replacing a hand has traditionally been difficult and costly given the complexity of movement and sensation in the hand, these designs often allow affordable and basic alternatives to expensive prosthetics, often with just the cost of materials. In most cases, a client may go to the site and print or request a hand using the site’s design.

These projects provide users not only with low cost options for prosthetics and mechanical limbs, but can also help build communities for all those involved.  Some designs are myoelectric and have motors, some do not and work with pulley systems mimicking the natural movement of the hand. Below are just a few of the exciting current sites that are changing the way we approach options for those with hand and wrist amputations.

e-NABLE

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        Multiple open-source designs of various hands that provide amputees with low cost prosthetic options are only one component of the amazing e-NABLE community.  An international community of designers, engineers, users, occupational therapists, 3D printer owners, and anyone else interested in joining participate by putting themselves on the map and express what they need or can provide. If someone in South Africa needs a hand 3D printed, for example, they can contact the organization and find someone nearby with a 3D printer.  Originally starting as on option for children, the designs are geared toward adults as well. There are multiple designs on the site, with instructional videos and practical tips on assembly. The google+ community discusses current projects, ways to improve designs, and shares thoughts and ideas.

3D Printing in Prosthetics: Open Source 3D Printed Prosthetics for Hand Amputees

Biohand

        Biohand is another great open source project born out of Brazil. Designed with about a $300 materials cost in mind, this will be another great low cost option once completed for amputees.

Able to lift up to 2 kg in testing, one of the amazing features of this hand is that each finger is controlled individually by the actuators, while a bar links the four digits to provide synchronization of movement. Meanwhile, the thumb has 2 degrees of freedom, meaning 2 different directions of joint motion. This allows the user to both bend/straighten the thumb and twist it, adding to the variety of movement in the hand and improving grip. There is a forum where users can discuss design and alterations, and the hand itself has very impressive components.
3D Printing in Prosthetics: Open Source 3D Printed Prosthetics for Hand Amputees

Exii

        HACKberry by Exii from Japan is not only aesthetically beautiful but also designed with a great variety of practical applications. Developed with building a community in mind, Exii is designing this bionic hand so that developers and users throughout the world can build on the design presented, ‘hacking’ it for improvement.  A forum has already been created where the community can discuss anything from sensors to design to hardware purchase.

        The fine grip of the HACKberry bionic hand allows users to write, flip a page, zip, and hold irregular and small objects.
3D Printing in Prosthetics: Open Source 3D Printed Prosthetics for Hand Amputees

Open Bionics

       Based in the UK, Open Bionics also addresses the worldwide and costly problem of amputation by providing an open source 3D printed hand design.

The Adams Hand, still in development, is a strong and flexible bionic hand with an actuator that controls all 5 fingers. Made with the customer in mind, Open Bionics plans to costumfit all hands for its users.  Hands are designed to be flexible, lightweight, and durable. The design is beautiful, and can be altered for color as well.