RESEARCH FOUNDATIONS
Built on published research.
Com&Sens is a spin-off of Ghent University. Our sensors and software build on more than 14 years of published research on fiber Bragg grating (FBG) sensors embedded in composites.
The 47 papers below are co-authored by Eli Voet (CEO) and Geert Luyckx (COO) with colleagues at Ghent University and partner labs across Europe. They are grouped by topic, newest first. Each title links to the publisher through its DOI.
Fiber egress and connection FBG embedded in composites Fiber integration Manufacturing and residual strain Fatigue, impact and harsh environments Bonded sensors and adhesive joints Interrogation and miniaturized systems Civil and infrastructure structures
01 · 3 PAPERS
Fiber egress and connection
An embedded sensor is only useful if you can reach it. These papers show how to connect fibers that leave a composite part, including after machining.
2024 · Proceedings of SPIE, Optical Fibers and Sensors for Medical Diagnostics, Treatment, and Environmental Applications XXIV
Aluminosilicate glass waveguide platform for connecting optical fiber sensors embedded in composite materials
Thibault Juwet, Eli Voet, Jeroen Missinne
Lays out the building blocks of a laser-written glass connector that links an embedded sensing fiber to the outside, where standard connectors and splices cannot be used.
2020 · II European Conference on Multifunctional Structures (EMuS 2020)
A Technology to (re-)Connect Optical Fibres Embedded in Composite Structures
Jindrich Windels, Jeroen Missinne, Eli Voet, Geert Van Steenberge, Geert Luyckx
Shows a low-loss way to connect, and repair if needed, an FBG fiber embedded in a composite part, so the part can be made without special care for the exit fiber.
2017 · IEEE Photonics Technology Letters
Low-Loss Connection of Embedded Optical Fiber Sensors Using a Self-Written Waveguide
Jeroen Missinne, Geert Luyckx, Eli Voet, Geert Van Steenberge
Exposes the embedded fiber end in a cross-section of the part, then grows a polymer waveguide that bridges it to an external fiber with low optical loss.
02 · 17 PAPERS
FBG embedded in composites: strain transfer and multi-axial sensing
How strain in the laminate reaches the grating, and how to read more than one strain component from a single embedded fiber.
2015 · Smart Materials and Structures
Microstructured optical fiber Bragg grating as an internal three-dimensional strain sensor for composite laminates
Camille Sonnenfeld, Geert Luyckx, Sanne Sulejmani, Thomas Geernaert, S. Eve, Moussa Gomina, Karima Chah, Paweł Mergo, Wacław Urbańczyk, Hugo Thienpont, Joris Degrieck, Francis Berghmans
Uses a pair of purpose-designed microstructured FBGs to measure strain along all three principal directions inside a laminate, backed by a model and coupon tests.
2014 · Proceedings of SPIE 9226, Nanophotonics and Macrophotonics for Space Environments VIII
Internal strain monitoring in composite materials with embedded photonic crystal fiber Bragg gratings
Thomas Geernaert, Sanne Sulejmani, Camille Sonnenfeld, Karima Chah, Geert Luyckx, Nicolas Lammens, Eli Voet, Martin Becker, Hugo Thienpont, Francis Berghmans
Shows that dedicated photonic crystal fibers make embedded FBGs sensitive to strain across the fiber axis, not only along it.
2013 · NDT & E International
Residual strain-induced birefringent FBGs for multi-axial strain monitoring of CFRP composite laminates
Geert Luyckx, Eli Voet, Nicolas Lammens, Wim De Waele, Joris Degrieck
Uses the birefringence that cure-induced residual strain creates in an embedded FBG to read multi-axial strain in CFRP laminates.
2012 · Emerging Technologies in Non-Destructive Testing V
In-situ local strain measurement in textile composites with embedded optical fibre sensors
Subbareddy Daggumati, Eli Voet, Ives De Baere, Wim Van Paepegem, Joris Degrieck, Jian Hua Xu, Stepan Vladimirovitch Lomov, Ignace Verpoest
Measures local strain inside a woven composite with embedded fibers to test the assumptions behind unit-cell models.
2011 · Sensors
Microstructured Optical Fiber Sensors Embedded in a Laminate Composite for Smart Material Applications
Camille Sonnenfeld, Sanne Sulejmani, Thomas Geernaert, S. Eve, Nicolas Lammens, Geert Luyckx, Eli Voet, Joris Degrieck, Wacław Urbańczyk, Paweł Mergo, Martin Becker, Hartmut O. Bartelt, Francis Berghmans, Hugo Thienpont
Embeds FBGs written in a birefringent microstructured fiber and reaches a transverse strain sensitivity ten times higher than earlier published values.
2011 · 2011 IEEE Sensors Conference
Towards micro-structured optical fiber sensors for transverse strain sensing in smart composite materials
Sanne Sulejmani, Camille Sonnenfeld, Thomas Geernaert, Francis Berghmans, Hugo Thienpont, S. Eve, Nicolas Lammens, Geert Luyckx, Eli Voet, Joris Degrieck, Wacław Urbańczyk, Paweł Mergo, Martin Becker, Hartmut O. Bartelt
Reports a second-generation microstructured fiber sensor for transverse strain in carbon composites.
2011 · Proceedings of SPIE 7753, 21st International Conference on Optical Fiber Sensors (OFS21)
Experimental validation of a numerically determined multi-axial strain transfer from CFRP-laminates to embedded Bragg sensors
Geert Luyckx, Eli Voet, Nicolas Lammens, Wim De Waele, Joris Degrieck
Checks on cross-ply laminates the predicted transfer of multi-axial strain from the composite to an embedded FBG.
2011 · Proceedings of SPIE 7753, 21st International Conference on Optical Fiber Sensors (OFS21)
Evaluation of the transversal strain state in a satin weave composite using fibre Bragg gratings
Eli Voet, Geert Luyckx, Joris Degrieck, Wim Van Paepegem
Uses embedded FBGs with 80 and 125 µm cladding to map how transverse strain varies inside a woven thermoplastic composite.
2010 · Sensors
Strain Measurements of Composite Laminates with Embedded Fibre Bragg Gratings: Criticism and Opportunities for Research
Geert Luyckx, Eli Voet, Nicolas Lammens, Joris Degrieck
Reviews the practical pitfalls of strain measurement with embedded FBGs, most of them tied to the embedding process, and sets out what research should address.
2010 · Smart Materials and Structures
Multi-axial strain transfer from laminated CFRP composites to embedded Bragg sensor: I. Parametric study
Geert Luyckx, Eli Voet, Wim De Waele, Joris Degrieck
Quantifies by simulation how strain in a CFRP laminate reaches an embedded FBG, and which parameters drive the difference.
2010 · Smart Materials and Structures
Multi-axial strain transfer from laminated CFRP composites to embedded Bragg sensor: II. Experimental validation
Eli Voet, Geert Luyckx, Wim De Waele, Joris Degrieck
Tests the strain transfer model of part I against instrumented laminates.
2009 · IEEE Photonics Technology Letters
Transversal Load Sensing With Fiber Bragg Gratings in Microstructured Optical Fibers
Thomas Geernaert, Geert Luyckx, Eli Voet, Tomasz Nasiłowski, Karima Chah, Martin Becker, Hartmut O. Bartelt, Wacław Urbańczyk, Jan Wójcik, Wim De Waele, Joris Degrieck, Herman Albert Terryn, Francis Berghmans, Hugo Thienpont
Shows that FBGs in birefringent microstructured fiber can be embedded in CFRP and give a linear response to transverse load.
2009 · IEEE Photonics Technology Letters
Response of FBGs in Microstructured and Bow Tie Fibers Embedded in Laminated Composite
Geert Luyckx, Eli Voet, Thomas Geernaert, Karima Chah, Tomasz Nasiłowski, Wim De Waele, Wim Van Paepegem, Martin Becker, Hartmut O. Bartelt, Wacław Urbańczyk, Jan Wójcik, Joris Degrieck, Francis Berghmans, Hugo Thienpont
Compares two birefringent fiber types embedded in CFRP: similar strain sensitivity, but lower temperature dependence for the microstructured fiber.
2009 · Proceedings of SPIE 7503, 20th International Conference on Optical Fibre Sensors (OFS20)
Response of embedded fibre Bragg gratings: strain transfer effects
Eli Voet, Geert Luyckx, Joris Degrieck
Combines finite element models and tests on small laminates to determine how transverse load reaches an embedded FBG.
2008 · Advances in Science and Technology 56 (CIMTEC 2008)
Strain Monitoring of FRP Elements Using an Embedded Fibre Optic Sensor
Geert Luyckx, Eli Voet, Wim De Waele, Wim Van Paepegem, Joris Degrieck, Johan Vlekken
Relates the two Bragg peaks of an FBG in polarization-maintaining fiber to the strain field inside a CFRP laminate.
2007 · Insight: Non-Destructive Testing and Condition Monitoring
Three-dimensional strain and temperature monitoring of composite laminates
Geert Luyckx, Wim De Waele, Joris Degrieck, Wim Van Paepegem, Johan Vlekken, S Vandamme, Karima Chah
Presents an FBG sensor design, from an ESA co-funded project, that measures multi-axial strain and temperature in space-qualified composite elements.
2006 · Optical Fiber Sensors Conference (OFS 2006)
Fiber Optic Sensing System for Discriminating Multi-Axial Strain Components in Composite Elements
Geert Luyckx, Wim De Waele, Joris Degrieck, Wim Van Paepegem, Johan Vlekken, Karima Chah
First results of an FBG configuration that separates axial and transverse strain components in composites.
03 · 6 PAPERS
Fiber integration: resin pockets, coatings and placement
What an embedded fiber does to the part around it, and how to keep that effect small.
2016 · Composite Structures
Finite element prediction of resin pocket geometries around arbitrary inclusions in composites: Case study for an embedded optical fiber interrogator
Nicolas Lammens, Geert Luyckx, Wim Van Paepegem, Joris Degrieck
Extends the resin pocket model to any embedded object, with an optical interrogator chip as the case study.
2015 · Composite Structures
Finite element prediction of resin pocket geometry around embedded optical fiber sensors in prepreg composites
Nicolas Lammens, Geert Luyckx, Eli Voet, Wim Van Paepegem, Joris Degrieck
Predicts the resin-rich pocket that forms around an embedded fiber in prepreg laminates.
2015 · Smart Materials and Structures
Optimization of coating diameter of fiber optic sensors embedded in composite structures under arbitrary loading conditions
Nicolas Lammens, Geert Luyckx, Eli Voet, Wim Van Paepegem, Joris Degrieck
Gives a method to choose the coating of an embedded fiber so it causes the least stress concentration in the host composite.
2015 · Sensors
A Micro-Computed Tomography Technique to Study the Quality of Fibre Optics Embedded in Composite Materials
Gabriele Chiesura, Geert Luyckx, Eli Voet, Nicolas Lammens, Wim Van Paepegem, Joris Degrieck, Manuel Dierick, Luc Van Hoorebeke, Pieter Vanderniepen, Sanne Sulejmani, Camille Sonnenfeld, Thomas Geernaert, Francis Berghmans
Shows that X-ray micro-CT can check, without cutting the part, how well a fiber is embedded in CFRP.
2015 · Structural Health Monitoring 2015 (IWSHM)
FE Tool for Drape Modelling and Resin Pocket Prediction of Fully Embedded Optical Fiber Sensor system
Nicolas Lammens, Gabriele Chiesura, Tahira J. Ahmed, Anders Brodsjo, Eli Voet, Geert Luyckx, Wim Van Paepegem, Joris Degrieck
Covers a placement head that lays the sensing fiber automatically during manufacturing, and models resin pockets around the embedded system.
2007 · Journal of Thermoplastic Composite Materials
Strain Monitoring in Thermoplastic Composites with Optical Fiber Sensors: Embedding Process, Visualization with Micro-tomography, and Fatigue Results
Ives De Baere, Eli Voet, Wim Van Paepegem, Johan Vlekken, Veerle Cnudde, Bert Masschaele, Joris Degrieck
Details how FBGs are embedded in thermoplastic composites, checks the result with micro-tomography and compares fatigue readings with an extensometer.
04 · 5 PAPERS
Manufacturing and residual strain
Sensors placed during production record curing and residual strain, from the first ply.
2016 · Sensors
RTM Production Monitoring of the A380 Hinge Arm Droop Nose Mechanism: A Multi-Sensor Approach
Gabriele Chiesura, Alfredo Lamberti, Yang Yang, Geert Luyckx, Wim Van Paepegem, Steve Vanlanduit, Jan Vanfleteren, Joris Degrieck
Embeds FBGs, cure sensors and thermocouples in an aircraft part and follows it through resin transfer moulding, without modifying the mould.
2013 · Composites Part A: Applied Science and Manufacturing
Residual strain monitoring of out-of-autoclave cured parts by use of polarization dependent loss measurements in embedded optical fiber Bragg gratings
Nicolas Lammens, Damien Kinet, Karima Chah, Geert Luyckx, Christophe Caucheteur, Joris Degrieck, Patrice Mégret
Measures residual strain in out-of-autoclave parts from the polarization behaviour of embedded FBGs.
2013 · Proceedings of SPIE, Micro-structured and Specialty Optical Fibres II
Embedded fiber Bragg gratings in photonic crystal fiber for cure cycle monitoring of carbon fiber-reinforced polymer materials
Camille Sonnenfeld, Geert Luyckx, Francis Collombet, Yves-Henri Grunevald, Bernard Douchin, Laurent Crouzeix, Mauricio Torres, Thomas Geernaert, Sanne Sulejmani, S. Eve, Moussa Gomina, Karima Chah, Paweł Mergo, Hugo Thienpont, Francis Berghmans
Tracks out-of-plane strain during curing with a temperature-insensitive photonic crystal fiber FBG.
2012 · Emerging Technologies in Non-Destructive Testing V
Cure monitoring of cross-ply composite laminates with an encapsulated fibre Bragg grating
Geert Luyckx, Nicolas Lammens, Joris Degrieck, Eli Voet
Follows the internal strain of a laminate through its cure cycle to see how residual strain builds up.
2007 · Conference paper (Zenodo archive)
Process monitoring with FBG sensors during vacuum infusion of thick composite laminates
Patricia P. Parlevliet, Eli Voet, Harald E. N. Bersee, A. Beukers
Monitors temperature and strain gradients through laminates thicker than 20 mm during vacuum infusion.
05 · 7 PAPERS
Fatigue, impact and harsh environments
Embedded FBGs following composite parts through fatigue, impacts and simulated orbit conditions.
2024 · Sensors
Monitoring of Composite Structures for Re-Usable Space Applications Using FBGs: The Influence of Low Earth Orbit Conditions
Thibault Juwet, Geert Luyckx, Alfredo Lamberti, Frank Creemers, Eli Voet, Jeroen Missinne
Shows that CFRP coupons with embedded FBGs keep their strength and their sensing accuracy after thermal vacuum cycles that simulate low Earth orbit.
2017 · Sensors
Detection, Localization and Quantification of Impact Events on a Stiffened Composite Panel with Embedded Fiber Bragg Grating Sensor Networks
Alfredo Lamberti, Geert Luyckx, Wim Van Paepegem, Ali Rezayat, Steve Vanlanduit
Detects, locates and sizes impacts on a stiffened composite panel with a network of embedded FBGs.
2017 · Proceedings of SPIE 10323, 25th International Conference on Optical Fiber Sensors (OFS25)
Dynamic 3D strain measurements with embedded micro-structured optical fiber Bragg grating sensors during impact on a CFRP coupon
Sidney Goossens, Thomas Geernaert, Ben Dieter De Pauw, Alfredo Lamberti, Steve Vanlanduit, Geert Luyckx, Gabriele Chiesura, Hugo Thienpont, Francis Berghmans
Measures how strain evolves in three directions inside a CFRP coupon during an impact.
2015 · Sensors
Dynamic Strain Measurements on Automotive and Aeronautic Composite Components by Means of Embedded Fiber Bragg Grating Sensors
Alfredo Lamberti, Gabriele Chiesura, Geert Luyckx, Joris Degrieck, Markus Kaufmann, Steve Vanlanduit
Uses embedded FBGs to characterize the vibration of a carbon automotive control arm and a glass-fiber aircraft hinge arm, validated with a laser vibrometer.
2015 · Emerging Technologies in Non-Destructive Testing VI
Micro-CT as a well-established technique to investigate the internal damage state of a composite laminate subjected to fatigue
Gabriele Chiesura, Geert Luyckx, Eli Voet, Wim Van Paepegem, Joris Degrieck, Matthieu Boone, J Dhaene, Luc Van Hoorebeke
Follows damage around embedded fibers of different diameters over millions of fatigue cycles.
2009 · Optics and Lasers in Engineering
On the feasibility of optical fibre sensors for strain monitoring in thermoplastic composites under fatigue loading conditions
Ives De Baere, Geert Luyckx, Eli Voet, Wim Van Paepegem, Joris Degrieck
Assesses whether embedded fiber sensors can follow strain in thermoplastic composites under fatigue loading.
2008 · Advances in Science and Technology 56 (CIMTEC 2008)
High Strain Monitoring during Fatigue Loading of Thermoplastic Composites Using Imbedded Draw Tower Fibre Bragg Grating Sensors
Eli Voet, Geert Luyckx, Ives De Baere, Joris Degrieck, Johan Vlekken, E Jacobs, Hartmut O. Bartelt
Shows that high-strength FBGs embedded in carbon thermoplastic coupons keep tracking strain without degradation over more than 500,000 cycles at 0.51% strain.
06 · 4 PAPERS
Bonded sensors and adhesive joints
When embedding is not an option: sensors bonded on a surface or placed in a bond line.
2018 · Advanced Engineering Materials
Thin and Flexible Polymer Photonic Sensor Foils for Monitoring Composite Structures
Jeroen Missinne, Nuria Teigell Benéitez, Alfredo Lamberti, Gabriele Chiesura, Geert Luyckx, Marie-Aline Mattelin, Wim Van Paepegem, Geert Van Steenberge
Presents polymer foils down to 50 µm thick carrying Bragg grating rosettes for multi-axial strain, flexible enough to bond or embed.
2014 · Smart Materials and Structures
Disbond monitoring in adhesive joints using shear stress optical fiber sensors
Sanne Sulejmani, Camille Sonnenfeld, Thomas Geernaert, Geert Luyckx, Paweł Mergo, Wacław Urbańczyk, Karima Chah, Hugo Thienpont, Francis Berghmans
Places three shear stress fiber sensors in the bond line of a lap joint and follows disbonding under cyclic loading.
2013 · Optics Express
Shear stress sensing with Bragg grating-based sensors in microstructured optical fibers
Sanne Sulejmani, Camille Sonnenfeld, Thomas Geernaert, Geert Luyckx, Danny Van Hemelrijck, Paweł Mergo, Wacław Urbańczyk, Karima Chah, Christophe Caucheteur, Patrice Mégret, Hugo Thienpont, Francis Berghmans
Measures shear stress inside an adhesive joint with a microstructured FBG, at a sensitivity of about 60 pm/MPa.
2009 · Proceedings of SPIE 7503, 20th International Conference on Optical Fibre Sensors (OFS20)
Installation and test procedures of optical strain gauges for aeronautical applications
Jan Van Roosbroeck, Erwin Jacobs, Eli Voet, Johan Vlekken
Describes a fast, repeatable way to bond an FBG to a structure as an optical strain gauge, with a mounting pad and UV-curable adhesive.
07 · 2 PAPERS
Interrogation and miniaturized systems
Reading many gratings with compact hardware, down to a system embedded in the part.
2015 · IEEE Photonics Journal
Simultaneous Interrogation of Multiple Fiber Bragg Grating Sensors Using an Arrayed Waveguide Grating Filter Fabricated in SOI Platform
Andrea Trita, Eli Voet, Jan P. Vermeiren, Danaë Delbeke, Pieter Dumon, Shibnath Pathak, Dries Van Thourhout
Demonstrates a 2.2 × 1.5 mm silicon chip that reads several FBGs at once, with 2.5 pm resolution over a 50 nm range.
2015 · Emerging Technologies in Non-Destructive Testing VI
SMARTFIBER: Miniaturized optical-fiber sensor based health monitoring system
Nicolas Lammens, Geert Luyckx, Eli Voet, Wim Van Paepegem, Joris Degrieck
Summarizes the EU SMARTFIBER project: robotic lay-down of the sensing fiber and a monitoring system fully embedded in the part.
08 · 3 PAPERS
Civil and infrastructure structures
Fiber Bragg gratings beyond composite parts: pavements and bridges.
2024 · Bituminous Mixtures and Pavements VIII
Exploring the use of fiber Bragg grating sensors for monitoring the structural response of asphalt pavements
David Hernando, Ali Golmohammadi, Navid Hasheminejad, Wim Van den bergh, Eli Voet
Gives practical guidance on FBG sensors for measuring how asphalt pavements respond to traffic.
2023 · Life-Cycle of Structures and Infrastructure Systems (IALCCE 2023)
Embedded fibre optical strain monitoring of a bio-composite bridge
M. Weil, Yacine Bel-Hadj, Wout Weijtjens, Christof Devriendt, Y.-A. Janssens, Eli Voet
Reports data from 90 embedded strain and temperature sensors in a recyclable composite footbridge, with temperature compensation and modal tracking.
2019 · Infrastructures
Fiber Optics Sensors in Asphalt Pavement: State-of-the-Art Review
Patricia Kara De Maeijer, Geert Luyckx, Cedric Vuye, Eli Voet, Wim Van den bergh, Steve Vanlanduit, Johan Braspenninckx, Nele Stevens, Jurgen De Wolf
Reviews how fiber optic sensors placed inside asphalt pavements support long-term monitoring.
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