Fiber Bragg gratings sensors for extreme environment sensing

Over the past couple of decades, fiber Bragg gratings have been used effectively as sensors for a wide variety of applications. A rapid increase in the popularity of FBG sensors is explained by the numerous advantages that they provide. FBG sensors are superior to other traditional means of environment measurement. FBG sensors are immune to electromagnetic interference and are resistant to harsh environments and corrosion. FBG sensors can be multiplexed; this ability was originally developed for optical network applications, however, it can be exploited in order to create sensor geometries that are quasi-distributed. This technology can be used for real-time measurements of temperature, strain, deformation, etc. Some popular and promising applications of fiber optic sensors include structural health monitoring of civil structures, for haptic sensing for robot appendages, and ‘smart skins’ for ships or aerospace vehicles.

Distributed FBG sensors are utilized in the oil and gas sector by oil field service companies for temperature and pressure monitoring of oil well downhole and reservoirs. Harsh environments of  20 kpsi and 185◦C are common there; the use of FBG sensors provides accurate measurement and collection of all the data parameters important for the field.

FBG sensors can also be utilized in environments where high temperatures are prevalent. Such environments are often found within power plants, gas or aerospace turbines, combustion systems, etc. Most FBG temperature sensors are thermally stable at least up to 1000 ◦C in standard telecom fibers.

Another area of application for FBG temperature sensors is gas turbine monitoring. The FBG sensor arrays facilitate measurements of hot gas working temperatures within a turbine; this data is critical for safe, reliable, efficient, and cost-effective operation. Accurate measurements of the blades and vanes inside the turbines will allow preventing overheating of the turbine blades due to inhomogeneous combustions.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients. Our main goal is to deliver the best quality fiber optic products to our clients. We produce a wide range of fiber optic devices, including our cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems.

Fiber Bragg grating sensors for biomechanics and rehabilitation applications

Fiber Bragg grating sensors are becoming increasingly popular and attractive for biomechanics and rehabilitation applications due to their advantageous properties like small size, lightweight, biocompatibility, chemical inertness, multiplexing capability, and immunity to electromagnetic interference. FBG sensors have been utilized in a variety of different applications, such as aeronautics, automotive, civil engineering structure monitoring, and undersea oil exploration. The use of fiber optic sensors for biomechanics and rehabilitation applications is very recent. The full-scale implementation has not been done yet.

FBG strain sensors can be used to measure strain in bones, stresses in intervertebral discs, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments,  shrinkage stresses in bone cement during polymerization. FBG displacement sensors could be used to measure chest wall deformations, angles between body segments during gait. FBG sensors are especially useful in dental biomechanics.

Applications of fiber Bragg grating sensors in biomechanics and rehabilitation engineering:

  1. Monitoring of biomechanical behavior of the musculoskeletal system;

The measurement of strain on the bones is crucial for understanding bone diseases and in designing medical devices. The measurement of bone strain is conducted using FBG strain sensors, which helps to study the effects of fracture fixation plates. FBG strain sensors can also be used to understand to what extent the bone calcium loss affects the strain response of bone

  1. Strain measurement of bone cement;

Damage to bone cement caused by dynamic loading is one of the main causes of hip replacement failures. The studies of human bone models using FBG strain sensors could be useful to verify the action of the cement, both during the curing process and after consolidation.

  1. Pressure mapping and the measurement of contact forces and stresses of orthopedic joints;

The understanding of contact stress at orthopedic joints is necessary for prostheses research and biomechanics studies. Due to the flexibility and multiplexing capability, FBG sensors are suitable for irregular-shaped interface surfaces, like a knee joint.

  1. Measurement of pressure distribution at the intervertebral disc;

FBG pressure sensors have outperformed other means of measuring pressure distribution at the intervertebral disc due to the small size and biocompatibility.

  1. Dental biomechanics;

FBG sensors are already used in dental applications, for example, monitoring the force and temperature as a function of time in dental splints worn by patients suffering from sleep apnoea.

  1. Monitoring of chest wall movement during respiration.

The studies of biomechanics have benefited greatly from the implementation of FBG sensors to measure chest displacement during respiration. The FBG sensors are embedded into a chest deformable strap which is strained in accordance with the deformation of the chest.

If you are interested in Optromix FBG sensors, please contact us at info@optromix.com

The use of FBG sensors in intelligent textiles

Medical textiles are an exciting idea that has the potential to significantly improve people’s lives. The use of textiles for medical purposes has a long history, and they are still used in the healthcare industry today. Traditionally, the textile industry was confined to the production of fibers and fabrics; modern technology allows the applications of textiles to expand. Recently, important developments have been made in enhancing the capabilities of textiles to respond to environmental stimuli. These textiles are called smart textiles; they possess the properties of conventional textiles and also carry additional functional values.

Smart textiles correspond with a wide area of products, as well as studies, that enhance the usefulness and functionality of conventional fabrics by using woven or non-woven structures that connect with the environment or users. The structures have the capability to sense environmental conditions.

There are multiple kinds of smart textiles that are used nowadays, one of them being E-textiles, or electronic textiles. E-textiles include smart health monitoring devices and sensors within the clothing that sense and record the basic bodily functions like body temperature, respiration, the functioning of a heart, etc. The data collected by the sensors is then transmitted to healthcare centers or hospitals. Fiber optic technology is widely incorporated in smart textiles in the form of sensors. Fiber optic sensors are used due to multiple advantages that they present, like low zero drift, large bandwidth, flexibility, good accuracy, immunity to electromagnetic interference, etc. Over the years fiber optic sensors have also become cheap and easily accessible.

Different fiber Bragg grating sensors are used in a variety of smart fabrics. Some of the FBG sensors that are used in smart fabrics include:

  • Stretch-sensitive sensors;

FBG strain sensors are used for monitoring and sensing body parameters. The sensors are used for determining respiration, movement, blood pressure, heart rate.

  • Temperature sensing;

FBG temperature sensors provide temperature monitoring on skin surfaces

as well as the near-body environment. These sensors are often incorporated in combat clothing.

  • Sensing harness;

FBG strain sensors and FBG displacement sensors are placed to measure abdominal and thoracic movements caused due to breathing activity without corrupting signals or overlapping signals.

Optromix, Inc. is a U.S. manufacturer of innovative fiber optic products for the global market, based in Cambridge, MA. Our team always strives to provide the most technologically advanced fiber optic solutions for our clients. Optromix is a fast-growing vendor of fiber Bragg grating (FBG) products line: fiber Bragg grating sensors, FBG interrogators and multiplexers, Distributed Temperature Sensing (DTS) systems. We create and supply a broad variety of top-notch fiber optic solutions for the monitoring of various facilities all over the world.

If you are interested in Optromix FBG sensors, please contact us at info@optromix.com