Measurement In Real Time: Researchers Develop 3D-Printed Insoles

Did you know, the American Podiatric Medical Association (APMA) surveyed 1,000 US adults and found that 77% of Americans have experienced foot pain? Now, 3D-printed insoles are set to provide relief. The new development by researchers at the Swiss Federal Institute of Technology Zurich (ETH Zürich), Federal Institute of Technology in Lausanne (EPFL), and the Federal Laboratory for Materials Testing and Research (Empa) is designed to allow patients and athletes to track the progress of their therapy and training. The insole is equipped with integrated sensors that are designed to measure the sole pressure directly from the shoe, the team says in their scientific publication.

Whether in sports to optimize one’s own performance or to minimize foot-related complaints in everyday life – more and more people are benefiting from custom-made insoles. In most cases, however, the process of sole production takes a lot of time. A personal pressure profile of the feet must first be created for each customer. To do this, customers must step barefoot onto a pressure-sensitive mat so that the footprint can be recorded. The insole is then created by hand based on the individual pressure profile. This not only costs time, but is also limited to the performing facility.

3D printed insole with conductive tracks and sensors made of piezoelectric elements

The insoles, made using additive manufacturing, record the pressure patterns in the shoe in real-time, so the activity the wearer is performing becomes apparent – whether “someone is walking, running, climbing stairs or even carrying a heavy load on their back. In which case, the pressure shifts more to the heel,” says Gilberto Siqueira, co-project leader and senior research assistant at Empa and the Laboratory for Complex Materials at ETH Zurich. The sensors, AKA piezo elements, transform mechanical pressure into electrical signals, measuring both regular and shear forces.