Load cell for structural monitoring based on a microbend self-referenced fiber optic intensity sensor

This study develops microbend fiber optical sensor embedded in a composite laminate and demonstrates its capability of measuring applied pressure up to 750 kPa. The sensing configuration described in this work is a versatile structure for monitoring of static and dynamic physical parameters, requiring a small number of optical components and simple signal processing. Of significant importance is the concept of self-referencing which solves the problem of the referentiation of the optical power fluctuations along the optical system. The load cell shows interesting properties, namely the low cost of the microbend sensing head and the fiber optic based interrogation system. On top of that, the use of optical fibers overcomes some of the problems of conventional load cells, which are sensitive to a number of factors such as environment, durability of materials and presence of electromagnetic fields. Moreover, this sensing technology has also the potential to be integrated in multiplexed sensor networks.