Second Hackaday Prize 2015 goes to open source prosthetics by OpenBionics:
Nowadays most prosthetic hands cost dozens of thousands of USD. The OpenBionics initiative (www.openbionics.org) presents a new open-source design for highly functional prosthetic hands. The proposed hands cost less than 200$, weigh less than 300 gr and can be easily fabricated with off-the-shelf materials and rapid prototyping techniques (3D Printing).
A novel differential mechanism (based on the whiffletree) allows the user to block the motion of each finger independently and facilitates the execution of 144 different grasps with only 1 actuator. The design is based on parametric models of hand anthropometry studies
so it can easily be personalized to specific patients.OpenBionics is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Bio-inspired Compliant Robot Fingers with Soft Fingertips
The finger actuation and transmission system follows a bio-inspired design that structurally reproduces the flexion (with tendons driven through low-friction tubes) and extension (using elastomer materials) movements of human fingers. The structure of the finger is constructed with Plexiglas (acrylic) and the flexure joints are implemented with silicone sheets.
For the robot fingers we use also the following materials: 1) sponge like tape that is easily deformable (to enlarge contact patches, reduce contact forces impact to the grasped object and enhance stability), 2) rubber tape (to increase friction and constrain the sponge like tape on the robot phalanges) and 3) anti-slip tape (to maximize friction during contact, enhansing stability of grasps).
Thumb Mechanism
A selectively lockable toothed mechanism that can implement 9 different opposition configurations, is proposed for the thumb. The proposed mechanism substitutes the three Degrees of Freedom (DoF) that implement the human thumb opposition with only one rotational DoF. The proposed mechanism is completely stiff when it is locked and is not affected by torsional forces inherent in dynamic / unstructured environments. A separate tendon routing system is used for the thumb and its tendon is terminated to a separate servo pulley.
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Components
- 1 × HerkuleX DRS201. Servo motor (torque 24 Kg/cm)
- 1 × Arduino Micro. Micro-controller.
- 1 × Surface electromyography sensing kit. Low cost kit from Advancer Technologies for EMG based control.
- 1 × Plexiglas sheet (width: 4 mm, 2 mm). 1 sheet per width (400 x 600 mm).
- 1 × Silicone sheets (width: 4 mm, 5 mm, 6 mm). 200 mm per width for flexure joints.
- 5 × Deep v-groove (1.2 mm) 3 x 12 x 4 mm sealed pulley rail ball bearings. For tendon routing system.
- 1 × Various Nuts, Sockets, Rods, Washers & Fasteners. More details can be found in the assembly guide.
- 4 × Springs For the construction of the buttons of the differential mechanism.
- 1 × Dyneema fishing line (0.4 mm). Our design is tendon driven.
- 1 × Nylon fishing line (0.4 mm). To stich silicone sheets onto the rigid parts.
All components, videos and pictures, blueprints here: OpenBionics Affordable Prosthetic Hands • Hackaday.io
