Fuzzy sensors: the development of inexpensive structurally compatible sensor elements

摘要

Many of the sensor technologies considered for integration into "smart" materials systems have been adopted from a host of other applications. Consider, for example, fiber optics; these materials were originally designed for telecommunication and have since been modified to serve as effective sensor elements. The present research, by contrast, has focused on the development of a new generation of sensor specifically designed to meet a range of critical operational constraints. The sensor consists of conductive particles selectively distributed in a non-conductive matrix. The matrix could be an elastomer or the host matrix used in a polymer composite. Selective distribution of the particles allows for unprecedented amplification of the sensor signal, thus augmenting its ability to detect relatively weak disturbances in the host structure. The signals exhibit both analgo and digital-like response characteristics, and hence they have been called "fuzzy" sensors. The advantages of this approach include a practical sensor element that exhibits very low cost (less than 10 cents per sensor), structural compatibility with the host structure, and high sensitivity. The fuzzy sensors have been successfully implemented in a structural composite component and a real time data retrieval system has been developed.