At the Fraunhofer Institutes for Mechanics of Materials and for Environmental, Safety, and Energy Technology in Germany, researchers have been working on developing a process of making personalized shoe insoles for diabetic patients. People with advanced diabetes can suffer from neuropathy and peripheral vascular disease, turning the tissue of the soles fragile and easily damaged. To prevent pressure wounds, custom made insoles are produced that have different areas of softness and hardness that provide support while avoiding injury to specific spots on the foot. Nowadays the insoles are usually manually crafted for each patient’s needs, but the process is not systematic and often doesn’t produce optimal results.
The Fraunhofer team is using a laser to digitize a foot to obtain its nearly perfect volumetric representation inside a computer. The researchers then design an insole with varying properties throughout that will support the foot in some parts while avoiding pressure on others. Following, the insole is produced on a 3D printer using a thermoplastic polyurethane as the material.
The interior of the new insoles have different structural components such as triangles and wavy rods, each of which results in a material of different softness and strength. Using a variety of such structural components, the researchers are able to achieve precisely the parameters needed throughout the insole for each unique foot.