The CB-hand

Sammanfattning: The purpose of the thesis was to design and build an externally powered prosthetic hand. The hand should preferably have one or more new functionalities not found in other prostheses. The human hand is very complex, it contains over 30 muscles and at least 18 joints. In comparison, a complex and dexterous commercial prostheses has five actuators and eleven joints, but only one or two control signals. All in all making it essentially impossible to replace the human hand with an equal prosthesis. The concepts was developed after literature study and interviews. The concept was 3D printed, tested, evaluated and improved in cycles until a final prototype could be constructed and manufactured. The final prototype was mainly 3D-printed in plastic because of the design, quickness and viability; the design made it hard to manufacture in any other way. The exceptions are the gears, motors and shafts which were bought from suppliers. In the end, the assembly of the final prototype did not go as well as expected. The reason was mainly the accuracy and the fitting of the gears to the shafts; the accuracy of the measurements in the parts was not high enough, and the gears came loose.Thus, it is very hard to draw any conclusions about the design from it. What can be seen is that the idea of the design seems to work but requires some reworking. Finally, to get some real answers about its viability, it needs to be tested with a prototype of better build quality.