If your shoe is too tight, you probably shift your weight to relieve some pressure. Diabetics sometimes struggle with neuropathy in their feet, making it difficult to sense pinching. This can lead to wounds.
Researchers from the Fraunhofer Institutes for Mechanics of Materials and for Environmental, Safety, and Energy Technology in Germany are working with digital foot-mapping technology to create custom-made insoles.
“Digital foot mapping is already common practice,” said Tobias Ziegler, an Institute for Mechanics of Materials scientist. “As part of this project, we have now also completely digitized the insole production process. Using newly developed software, the orthopedic shoemaker can design an insole for an individual patient and can print out the result on a 3D printer.”
A soft material called thermoplastic polyurethane is already used in 3D printed insoles, but researchers are investigating other types of TPU that might be more suitable for the diabetic insoles.
“First we think about structures – straight rods, crooked arms, or triangles, for instance – then we produce a computer model of them, key in the data for a particular material, and simulate how rigid the result is under pressure,” said Ziegler. “Where does an insole need to soft, or more rigid? By altering the structure type, we can precisely determine the rigidity of the insole.”
The research team uses application-oriented load simulations to determine which structures are needed where to achieve the best results.
Once an insole is printed by research partners Explius, it is sent back to the researchers for testing the point of failure using tensile, abrasion, and bending tests. The first insole prototypes have already been tested using these methods.
Filed Under: 3D printing • additive manufacturing • stereolithography, Industrial automation