E-Knitted Textile with Polymer Optical Fibers for Friction and Pressure Monitoring in Socks

The objective of this paper is to study the ability of polymer optical fiber (POF) to be inserted in a knitted fabric and to measure both pressure and friction when walking. Firstly, POF, marketed and in development, have been compared in terms of the required mechanical properties for the insertion of the fiber directly into a knitted fabric on an industrial scale, i.e. elongation, bending rigidity, and minimum bending radius before plastic deformation. Secondly, the chosen optical fiber was inserted inside several types of knitted fabric and was shown to be sensitive to friction and compression. The knitted structure with the highest sensitivity has been chosen for sock prototype manufacturing. Finally, a feasibility study with an instrumented sock showed that it is possible to detect the different phases of walking in terms of compression and friction

Foot plantar pressure monitoring with CYTOP bragg gratings sensing system

In this paper, a polymer optical fiber (POF) sensing solution to monitor the pressure induced in the foot plantar surface is investigated. The paper shows the design and implementation of a platform with an array of 5 polymer optical fiber Bragg gratings (POFBGs) placed in key points to monitor the pressure on the foot surface during gait cycles and the body center mass displacements. The results showed a great response compared with solutions using silica optical fibers. A much high sensitivity and repeatability were achieved using the CYTOP fiber as well as proving that the advantages of POF is a viable and useful solution for this type of application for a future implementation of an integrated “in-shoe” CYTOP POFBGs sensor network