Dextra

Dextra is a printable human-sized robotic hand that is being developed as an open-source and affordable alternative to commercial robotic hand prosthesis. Although it has been designed to be used as a prosthesis, this robotic hand can also be used in education, research or more general applications in robotics. The key design points of Dextra are: adaptive grip, compact size, mechanical simplicity and ease of replication.

The mechanical design of Dextra is based on the finger module. A finger module comprises a compact linear actuator based on a geared DC micro motor, position feedback provided by a magnetic encoder, and the mechanical printable finger. This module is used in the four fingers of the hand, and the thumb is a variation of the same design.

To reduce the size, as well as the mechanical complexity of Dextra, the fingers are underactuated, that is, they have more degrees of freedom (DOF) than actuators. Each finger module has three DOF and one motor, while the thumb ha