3-D Printed Insoles Developed for Diabetes Patients

The list of advances in the field of 3-D printing keeps getting longer. Researchers from the Fraunhofer Institutes for Mechanics of Materials IWM and for Environmental, Safety, and Energy Technology UMSICHT are collaborating with industry partners in the process of producing digitalized insoles for people with diabetes by using new software and the use of 3-D printers. People diagnosed with diabetes may suffer from the nerves in their foot becoming atrophied. Specially made insoles promise relief because they are customized to be very soft in the area of the injury.

Health insurances companies are supporting the efforts of researchers to digitalize the entire process of making specialty insoles to allow the collection of scientific data on them.

LAUF, a German acronym for "laser-assisted construction of customized footwear," is the project funded by Germany's Federal Ministry of Education and Research.

"Digital foot mapping is already common practice. As part of this project, we have now also completely digitalized the insole production process," stated IWM scientist Dr. Tobias Ziegler. "Using newly developed software, the orthopedic shoemaker can design an insole for an individual patient and can print out the result on a 3-D printer."

IWM scientists have meanwhile been optimizing the three-dimensional structures when it is used for insoles. How soft or rigid insoles are relies not just on the material used, but also on how it is shaped. "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," Ziegler recounted. "Where does an insole need to be soft, or more rigid? By altering the structure type, we can precisely determine the rigidity of the insole."

The IWM team used application-oriented load simulations to resolve which structures are needed where to achieve the desired results. They tested the material's load-bearing strength and its expected durability. "We simulate the entire production process, too, in order to identify where there is potential for optimization," Ziegler explained. He also used this approach in relation to other materials and structures for 3-D printing.

In two or so years, this software might be available to orthopedic technicians through Instituto de Educação Tecnológica (IETEC), a member of the project.