The Design of the PLYOS prehensor

Nowadays forearm prosthesis are far from optimal, factors that need to be optimized are the mass, the price and the wear temperature of the prosthesis. This can be done by choosing cardboard as constructive material. In this report the relevant control mechanisms are investigated. A body powered prosthesis voluntary closing control is chosen as the activation mechanism. This mechanism has a new feature called passive closing. This feature enables the user to grip objects with di?erent grasp forces without exerting force with a harness. The created PLYOS prehensor can perform ?ve prehension patterns. The voluntary closing behavior of the prosthesis can be compared with the high end available prostheses, while being at least 30% lighter than the competition. The generated pinch force of 15 N is generated with an actuation force of 35.5 N. The plyos prehensor is also tested to lift 10 kg and it is able to do 20.000 cycles of gripping (activation force 60 N) and lifting (15 N). The wet strength of the prosthesis is good, it does not jam when it is wet, while it stays strong.BMEBioMechanical EngineeringMechanical, Maritime and Materials Engineerin