Optical sensors have hit their maturity and a new kind of systems is being developed. This paper deals with the development of a new sensing structure based on polymeric foils and optic fiber sensors, namely the Fiber Bragg Grating sensors. Sensor integration in polymeric foils, using industrial process is the proposed goal. To achieve this goal, Finite Element Analysis was used for prototype modeling and simulation. The model was subjected to loads and restraints in order to retrieve information about stress distribution and displacement of specific points. From the simulation was possible to predict the sections where the sensor should be positioned. A prototype was then fabricated using industrial processes. Tests indicate that the polymeric foil influence on the sensor performance may exist. However, the prototype was able of transferring the full deformation to the optical sensor. Moreover, the optical sensor, which is incorporated in the polymeric foil, is fully functional with high sensitivity, 0.6 picometer by microstrain, allowing deformation measurements, up to 1.2 millimeter.

Monitoring systems can already be found in common applications, from automotive to aeronautics or biomedical. However, the application of these monitoring systems has not yet been a very easy task, especially, at the sensor application step. A smart structure with sensing capabilities would allow to overcome the existing issues in the installation of sensor networks. As the size of this type of systems and the market requirements are significant, an industrial manufacturing process needed to be considered. An integrated solution based in Fiber Bragg Grating sensors embedded in PVC laminates was manufactured by industrial spread-coating process. The resultant structure is a temperature and strain sensitive foil that was characterized in terms of surface structure, optical response and overall performance. The integrated solution behavior had a slope of 0.8 pm by microstrain with a measurement range of 1.2 mm when the fiber was straight in the foil. Different fiber layouts were also tested and defined the minimum curve radius in 10 mm. The foil also presented a dimensional stability above 99%, ensuring the capability to sustain molding process. A mechanical analysis to evaluate the elongation capabilities and optical response was conducted. Three samples with different sensor positioning were subjected to the test. In the end, a sample, with the sensor in a 45à ° angle regarding the displacement axis, achieved the best compromise between maximum elongation range (25%) and optical response linearity. For the temperature response, a wavelength deviation of 1.7 nm was obtained for a 100 ºC temperature change.

This paper presents the fabrication and characterization of a polymeric foil able to sense deformation, gather sensitive information and send it for further analysis. Fiber Bragg Grating sensors are embedded in laminated polymeric sheets commonly used in the car’s flooring. The fabrication of the Bragg sensors and the integration of the optic sensors in the foil is described, using industrial fabrication processes. The obtained foil is capable of transferring the full deformation to the optic sensor and returning to the initial position when no deformation exists, providing good sensibility. Application of this sensing foil includes automobile chassis monitoring.

Electronic products, including sensors, are often used in harsh environments. However, many parameters, such as severe weather conditions, high electronic noise, or dangerous chemical compounds in situ, may compromise the required high reliability. Therefore, development of a reliable sensing solution for monitoring those extreme conditions may become a very challenging task. This paper presents a smart skin foil developed to meet this specific need. Fiber Bragg grating sensors, one of the most reliable sensor solutions nowadays, were embedded in a thin foil made of polyvinyl chloride, giving rise to a smart structure with high durability and high resistance, and a dimensional stability above 99%. In addition, the fabrication processes used are based on a technology that allows the development of large sensing areas. The sensing foil shows a linear stretching profile, with a slope of 7.8 nm per 1% elongation. After submitting the developed structure to temperature cycles, it revealed a thermal behavior of 0.1 nm/°C. Since the smart sensing structure was fabricated using available industrial fabrication processes, it is a feasible and ready-to-market solution.