PhosFOS is a research and technology development project co-funded by the European Commission.
Project Description
PHOSFOS (Photonic Skins For Optical Sensing) [1] aims to develop a flexible and stretchable foil or skin that integrates the optical sensing elements with optical and electrical devices as well as onboard signal processing and wireless communications. This flexible skin can be wrapped around, embedded in, attached and anchored to irregularly shaped and/or moving objects or bodies and will allow quasi-distributed sensing of mechanical quantities such as deformation, pressure, stress or strain [2]. This approach potentially gives a significant advnatage over conventional sensing systems because of the portablility of the resulting systems and the extended measurement range.
The sensing technology is based around sensing elements called Fiber Bragg Gratings (FBGs) that are fabricated in standard single core silica fibers, highly birefringent Microstructured fiber (MSF) and Plastic optical fiber (POF). The silica MSFs will be designed to exhibit almost zero temperature sensitivity to cope with the traditional temperature cross-sensitivity issues of conventional fiber sensors. These specialty fibers are being modeled, designed, fabricated within the programme. FBGS written in POF fibers will also be used since their length can be stretched up to 300% before breaking. This allows them to be used under conditions that would normally result in catastrophic failure of other types of strain sensors.
Once optimized the sensors are embedded into the sensing skin and on the interfaced to the peripheral optoelectronics and electronics.
The photonic skins developed in PHOSFOS have potential applications in continuously monitoring the integrity and the behavior of different kinds of structures in e.g. civil engineering (buildings, dams, bridges, roads, tunnels and mines), in aerospace (aircraft wings, helicopter blades) or in energy production (windmill blades) and therefore provide the necessary means for remote early failure, anomaly or danger warning. Applications in healthcare are also being investigated.
Key results so far
Latest results can be found on the PhosFOS EU webpage [1] and include the demonstration of a fully flexible opto-electronic foil [3].
One of the early results from the project was the successful demonstration of a repeatable method of joining the polymer fiber to standard silica fibre. This was a major development and allowed for the first time POF Bragg gratings to be used in real applications outside of the optics lab. One of the first uses for these sensors was in monitoring the strain of tapestries [4] shown in Figure 1, [5]. In this case conventional electrical strain sensors and silica fiber sensors were shown to be strengthening the tapestries in areas where they were fixed. Because the polymer devices are much more flexible they do not distort the material as much and therefore give a much most accurate measurement of the strain in flexible materials. Temperature and humidity sensing using a combined silica / POF fiber sensor has been demonstrated [6]. Combined strain, temperature and bend sensing has also been shown [7]. Using a fiber Bragg grating in an eccentric core polymer has been shown to yield a high sensitivity to bend [8].
Other recent progress includes the demonstration of birefringent photonic crystal fibers with zero polarimetric sensitivty to temperature [9], and a successful demonstration of transversal load sensing with fibre Bragg gratings in microstructured optic fibers [10].
Consortium
- [2], Vrije Universiteit Brussel
- [3], Interuniversitair Micro-Electronica Centrum VZW
- [4], Universiteit Gent
- [5], Politechnika Wroclawska
- [6], Uniwersitet Marie Curie Sklodowskiej
- [7], Aston University
- [8], Fiber Optic Sensors and Systems BVBA
- [9], Cyprus University of Technology
- [10], Astasense Limited
External links
References
- ^ http://www.phosfos.eu/
- ^ http://spie.org/x38859.xml?highlight=x2406&ArticleID=x38859
- ^ Fully flexible opto-electronic foil, E. Bosman, G. Van Steenberge, I. Milenkov, K. Panajotov, H. Thienpont, J. Bauwelinck, P. Van Daele, Journal of Selected Topics in Quantum Electronics, 2010
- ^ http://eprints.soton.ac.uk/68650/01/137_Lennard.pdf
- ^ http://spie.org/x39927.xml?ArticleID=x39927
- ^ Optical fibre temperature and humidity sensor, C. Zhang, W. Zhang, D.J. Webb, G.D. Peng, Electronics Letters, 46, 9, pp643-644, 2010, DOI: 10.1049/el.2010.0879
- ^ Bragg grating in polymer optical fibre for strain, bend and temperature sensing, X. Chen, C. Zhang, D.J Webb, G.-D. Peng , K. Kalli, Measurement Science and Technology, 2010
- ^ Highly Sensitive Bend Sensor Based on Bragg Grating in Eccentric Core Polymer Fiber, X. Chen, C. Zhang, D.J. Webb, K. Kalli, G.-D. Peng, A. Argyros, IEEE Sensors Journal, 2010
- ^ http://www.phosfos.eu/index.php/eng/Phosfos/Journals/Birefringent-photonic-crystal-fibers-with-zero-polarimetric-sensitivity-to-temperature
- ^ http://www.phosfos.eu/index.php/eng/Phosfos/Journals/Transversal-Load-Sensing-with-Fiber-Bragg-Gratings-in-Microstructured-Optical-Fibers