Use of Fiber Optic Microbending Sensors

Fiber optic microbending sensors are widely used for pressure, displacement, vibration, and health monitoring due to their high sensitivity, flexibility, and ability to operate in challenging environments.Healthcare and Wearable MonitoringMicrobending sensors are increasingly applied in wearable health devices to monitor vital signs such as heart rate (HR), respiratory rate (RR), and ballistocardiography (BCG). For example, a sandwich heterostructure multimode fiber Mach–Zehnder interferometer combined with a microbend deformer can detect subtle pressure changes from the human body, providing continuous, non-invasive monitoring comparable to commercial medical devices. These sensors offer high sensitivity, stability, and comfort, making them suitable for daily health supervision and early disease detection .Structural Health and Industrial MonitoringIn civil and industrial engineering, microbending sensors are used for structural health monitoring. They detect pressure, displacement, and vibration in bridges, buildings, and machinery by measuring light intensity changes caused by microbends in the fiber. The sensors' small size and mechanical flexibility allow them to be embedded in structures without affecting performance, enabling real-time monitoring of stress, strain, and deformation .Environmental and Disaster-Resilient SensingMicrobending sensors can operate in passive, energy-autonomous modes using scintillation fibers that convert ambient light into measurable signals. This makes them ideal for disaster-resilient sensor networks in infrastructure-limited environments, where they can monitor pressure changes or environmental conditions without external power sources .Other ApplicationsAdditional applications include:Liquid level and flow measurement: Detecting changes in fluid pressure or displacement.Chemical and biological sensing: Measuring pH, refractive index, or detecting specific biomolecules.Industrial process control: Monitoring rotation, vibration, or mechanical stress in machinery .AdvantagesFiber optic microbending sensors are favored because they are:Highly sensitive to small physical changes.Compact and flexible, allowing integration into wearable devices or embedded systems.Immune to electromagnetic interference, suitable for harsh industrial or medical environments.Capable of passive operation, reducing energy requirements in remote or disaster-prone areas . These characteristics make microbending sensors versatile tools across healthcare, structural monitoring, environmental sensing, and industrial applications, providing reliable and continuous measurement of physical parameters.