Common examples include microbend sensors and evanescent wave sensors, both of which utilize changes in light intensity to monitor physical parameters. Intensity-based fiber optic sensors offer several notable advantages. This information is then displayed in analog or digital form. What is a Fiber Optic Sensor? A fiber optic sensor measures a physical quantity by modulating the intensity. One example is injection holes of 150 microns and smaller, where the shape tolerances are in the submicrometer range. Threaded for easy mounting onto brackets and machine equipment. Suitable for installation in locations. An apparatus comprises a flexible filament structure, and a fiber optic sensor with a buffer material that locally bonds the fiber optic sensor to the flexible filament structure to create a bond between the fiber optic sensor and the flexible filament structure to transfer strain from the flexible. The integration of flexible materials with optical sensing technologies has advanced wearable optical biosensors, offering significant potential in personalized medicine, health monitoring, and disease prevention. This review summarizes the recent advancements in flexible materials for wearable. birth of fiber optic sensors.