Fraunhofer 3D Printed Exoskeleton Helps Patients Return to Daily Life

After accidents that damage tendons, a patient’s mobility is often severely limited. Hand injuries, in particular, can take a long time to heal and usually only recover fully through physiotherapy. For therapy, experts are increasingly using so-called exoskeletons, which are worn over the hand and specifically support hand and finger movements. Fraunhofer IWU has now developed an exoskeleton that can be tailored to each patient using 3D printing technologies.

More specifically, it uses innovative shape-memory alloys, stepper motors, and 3D printing technologies. The team emphasized that the exoskeleton must fit the patient’s hand perfectly. This is easier said than done, as every hand is different, and an exoskeleton that is not comfortable to wear can even negatively affect rehabilitation. This is where the unique properties of additive manufacturing come into play. Producing the exoskeleton with 3D printing technologies allows almost limitless customization of its structure.

A stepper motor and wires assist the hand’s movements.

The Technology Behind the 3D-printed Exoskeleton

The team chose SLS for this purpose, a technology in which a component is built layer by layer from powder, in this case, plastic powder. For optimal customization, a digital scan of the patient’s hand is created in advance. A parametric CAD model of the exoskeleton is then overlaid on this scan so that every parameter can be precisely adapted to the individual dimensions of the 3D scan.