Open Hand Project



The Dextrus hand uses electronics to interpret signals and convert these into hand movements. These electronics will do the following:

  1. Amplify the small Electomyographical signals from the user’s muscles and filter them to remove unwanted frequencies.
  2. Provide power to the various components and house the microcontroller.
  3. Amplify the signals from the microcontroller to power the motors.
  4. Read current feedback from the motors to know when an object is grasped.


The Dextrus hand contains many mechanical components including 3D printed plastic parts, tendons, nuts and bolts. Once the Dextrus design is complete, you’ll be able to find everything you need to build your own here on the website. Suppliers will be included where possible but it may be difficult to get international suppliers for all parts.

3D Models

The bulk of the Dextrus hand will be 3D printed in plastic. There are a variety of software packages available for 3D modelling, Solidworks is arguably the best for engineering design, however I’ll be using Blender for my designs because it’s free. Blender is a highly capable 3D modelling software generally used by artists and animators rather than designers, but can be applied to engineering designs as well.

The parts will be printed using the Lulzbot A0-101 3D printer. Various prototypes will be created and tested for strength, functionality and durability until I find the optimal design and once these are ready I’ll upload them to the website. I’ll also be creating a series of Blender tutorials to help people learn how to apply the software to small scale engineering designs.