Prosthetic Hand Concept

myminifactory

This object was entered in the MakeShaper Design Challenge (see all entries here). The concept of Interface Bonds is put to an interesting test with this model. Directly printing TPU onto PETG and ABS faces proves challenging, indicating a need for a better, more durable adhesion method for heavy use applications. Interface bonds utilize internal geometry to bond one material to another. In this design, flexible sections have links within the fingers to prevent them from loosening. This connection is very strong. The concept of Interface Bonds has numerous applications, including prosthetic limbs. Using a rigid material combined with a flexible material can achieve more realistic movements, lower costs, and easier customization for each patient. This model features internal geometry that allows fishing line to run through it, functioning as tendons. The recommended material for the joints is TPU 85A; 95A may be too stiff, and testing with 60A has not been done. The print was scaled up by a factor of 1.2, or 120%, for the test model. Depending on the fishing line's diameter used for tendons, printing even larger might be necessary.