Development and Characterization of Piezoresistive Nanocomposites for Sensing Applications
01 Jan 2017-
TL;DR: Anees et al. as mentioned in this paper fabricated hybrid nanocomposites with carbon nanotube (CNT) sheet and graphene nanoplatelets (GNP) as fillers with epoxy matrix.
Abstract: Anees, Muhammad MSAE, Embry-Riddle Aeronautical University, November 2017. Development and characterization of piezoresistive nanocomposites for sensing applications. Carbon nanotube based hybrid nanocomposites are known to exhibit remarkable electrical and mechanical properties with many potentials in strain and damage sensing applications. In this work, we fabricate hybrid nanocomposites with carbon nanotube (CNT) sheet and graphene nanoplatelets (GNP) as fillers with epoxy matrix. An improvement in both electrical conductivity and piezoresistivity is observed with the combination of CNTs and GNPs, indicating the formation of efficient hybrid conductive networks for strain and electrical transfer in the material. Different matrix materials have been compared to investigate the effect of matrix and to choose the one that yields increased strains, flexibility, and electromechanical response. The electromechanical behavior of the hybrid composites is investigated both under static and dynamic loading at various frequencies with induced levels of strains, and has shown positive response under all tested conditions. Digital image correlation has been used to investigate the strain variation within the specimen both during static and dynamic testing. As these sensors will be tested for damage sensing in space applications for inflatable habitat under Micrometeoroid and Orbital Debris (MMOD) impact, the sensitivity of the sensor with 3 mm impact holes is evaluated using four point probe electrical resistivity measurements. An array of these sensors when sandwiched between soft good layers in a space habitat can act as a damage detection layer for inflatable structures. A computer program is developed to determine the event of impact, its severity and the location on the sensing layer for active
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01 Jul 2013
TL;DR: A method of determining the size, location, and direction of damage in a multilayered structure and can be used to generate both diagnostic and prognostic information related to the health of layer composite structures, which will be essential if such systems are utilized for space exploration.
Abstract: Current designs for inflatable or semi-rigidized structures for habitats and space applications use a multiple-layer construction, alternating thin layers with thicker, stronger layers, which produces a layered composite structure that is much better at resisting damage. Even though such composite structures or layered systems are robust, they can still be susceptible to penetration damage. The ability to detect damage to surfaces of inflatable or semi-rigid habitat structures is of great interest to NASA. Damage caused by impacts of foreign objects such as micrometeorites can rupture the shell of these structures, causing loss of critical hardware and/or the life of the crew. While not all impacts will have a catastrophic result, it will be very important to identify and locate areas of the exterior shell that have been damaged by impacts so that repairs (or other provisions) can be made to reduce the probability of shell wall rupture. This disclosure describes a system that will provide real-time data regarding the health of the inflatable shell or rigidized structures, and information related to the location and depth of impact damage. The innovation described here is a method of determining the size, location, and direction of damage in a multilayered structure. In the multi-dimensional damage detection system, layers of two-dimensional thin film detection layers are used to form a layered composite, with non-detection layers separating the detection layers. The non-detection layers may be either thicker or thinner than the detection layers. The thin-film damage detection layers are thin films of materials with a conductive grid or striped pattern. The conductive pattern may be applied by several methods, including printing, plating, sputtering, photolithography, and etching, and can include as many detection layers that are necessary for the structure construction or to afford the detection detail level required. The damage is detected using a detector or sensory system, which may include a time domain reflectometer, resistivity monitoring hardware, or other resistance-based systems. To begin, a layered composite consisting of thin-film damage detection layers separated by non-damage detection layers is fabricated. The damage detection layers are attached to a detector that provides details regarding the physical health of each detection layer individually. If damage occurs to any of the detection layers, a change in the electrical properties of the detection layers damaged occurs, and a response is generated. Real-time analysis of these responses will provide details regarding the depth, location, and size estimation of the damage. Multiple damages can be detected, and the extent (depth) of the damage can be used to generate prognostic information related to the expected lifetime of the layered composite system. The detection system can be fabricated very easily using off-the-shelf equipment, and the detection algorithms can be written and updated (as needed) to provide the level of detail needed based on the system being monitored. Connecting to the thin film detection layers is very easy as well. The truly unique feature of the system is its flexibility; the system can be designed to gather as much (or as little) information as the end user feels necessary. Individual detection layers can be turned on or off as necessary, and algorithms can be used to optimize performance. The system can be used to generate both diagnostic and prognostic information related to the health of layer composite structures, which will be essential if such systems are utilized for space exploration. The technology is also applicable to other in-situ health monitoring systems for structure integrity.
2 citations
01 Jan 2019
TL;DR: In this paper, the authors presented fabrication and testing of hybrid nanocomposites with carbon nanotubes (CNT) and coarse graphene nanoplatelets (GNP) as fillers and flexible epoxy matrix, that are proposed to be used for sensing the impact damage by micrometeoroid orbital debris (MMOD) in space inflatable structures.
Abstract: Future space exploration requires easy-to-transport, and easy-to-build and deploy space habitats. NASA and Bigelow Aerospace have collaborated so that human habitation can be made safe and easy with inflatable space habitats (Litteken, 2017). One of the biggest threats faced by these structures in outer space is impact damage by micrometeoroid orbital debris (MMOD) traveling at velocities as high as 15 km/s (Lemmens, Krag, Rosebrock, & Carnelli, 2013). This work presents fabrication and testing of hybrid nanocomposites with carbon nanotubes (CNT) and coarse graphene nanoplatelets (GNP) as fillers and flexible epoxy matrix, that are proposed to be used for sensing the impact damage by MMOD in space inflatable structures. CNT and GNP were chosen as fillers owing to their excellent electrical properties and piezoresistivity. A new method was developed to cut graphite sheet (composed of GNPs) in laser marker and distribute it in patterns on carbon nanotube sheet (buckypaper) in epoxy matrix. Piezoresitivity tests were carried out and results were compared with percolation-based Monte Carlo simulations from past research. A hypervelocity impact test was designed and executed at the University of Dayton Research Institute, Ohio, to test the response of the sensors to hypervelocity impacts. Aluminum spheres of 3 mm diameter and 4.5 mm diameter were accelerated to 7 km/s and shot at the sensors, and results were recorded during and after the test. A periodic scanning multichannel control circuit was designed to power the sensors. LabVIEW codes were used for data acquisition and recognizing the location of the damage. The results proved that the hybrid CNT-GNP/epoxy nanocomposites can be used to create a damage detection system which would not only detect the impact damage caused by MMOD of 3mm diameter traveling at 7km/s but also discern its location and
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References
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22 Dec 2003
TL;DR: In this paper, the second-rank tensors of a tensor were modeled as tensors and they were used to model the deformation of polycrystalline materials and their properties.
Abstract: Chapter 1. Introduction.1.1 Strain1.2 Stress.1.3 Mechanical Testing.1.4 Mechanical Responses to Deformation.1.5 How Bonding Influences Mechanical Properties.1.6 Further Reading and References.1.7 Problems.Chapter 2. Tensors and Elasticity.2.1 What Is a Tensor?2.2 Transformation of Tensors.2.3 The Second Rank Tensors of Strain and Stress.2.4 Directional Properties.2.5 Elasticity.2.6 Effective Properties of Materials: Oriented Polycrystals and Composites.2.7 Matrix Methods for Elasticity Tensors.2.8 Appendix: The Stereographic Projection.2.9 References.2.10 Problems.Chapter 3. Plasticity.3.1 Continuum Models for Shear Deformation of Isotropic Ductile Materials.3.2 Shear Deformation of Crystalline Materials.3.3 Necking and Instability.3.4 Shear Deformation of Non Crystalline materials.3.5 Dilatant Deformation of Materials.3.6 Appendix: Independent Slip Systems.3.7 References.3.8 Problems.Chapter 4. Dislocations in Crystals.4.1 Dislocation Theory.4.2 Specification of Dislocation Character.4.3 Dislocation Motion.4.4 Dislocation Content in Crystals and Polycrystals.4.5 Dislocations and Dislocation Motion in Specific Crystal Structures.4.6 References.4.7 Problems.Chapter 5. Strengthening Mechanisms.5.1 Constraint Based Strengthening.5.2 Strengthening Mechanisms in Crystalline Materials.5.3 Orientation Strengthening.5.4 References.5.5 Problems.Chapter 6. High Temperature and Rate Dependent Deformation.6.1 Creep.6.2 Extrapolation Approaches for Failure and Creep.6.3 Stress Relaxation.6.4 Creep and Relaxation Mechanisms in Crystalline Materials.6.5 References.6.6 Problems.Chapter 7. Fracture of Materials.7.1 Stress Distributions Near Crack Tips.7.2 Fracture Toughness Testing.7.3 Failure Probability and Weibull Statistics.7.4 Mechanisms for Toughness Enhancement of Brittle Materials.7.5 Appendix A: Derivation of the Stress Concentration at a Through Hole.7.6 Appendix B: Stress Volume Integral Approach for Weibull Statistics.7.7 References.7.8 Problems.Chapter 8. Mapping Strategies for Understanding Mechanical Properties.8.1 Deformation Mechanism Maps.8.2 Fracture Mechanism Maps.8.3 Mechanical Design Maps.8.4 References.8.5 Problems.Chapter 9. Degradation Processes: Fatigue and Wear.9.1 Cystic Fatigue of materials.9.2 Engineering Fatigue Analysis.9.3 Wear, Friction, and Lubrication.9.4 References.9.5 Problems.Chapter 10. Deformation Processing.10.1 Ideal Energy Approach for Modeling of a Forming Process.10.2 Inclusion of Friction and Die Geometry in Deformation Processes: Slab Analysis.10.3 Upper Bound Analysis.10.4 Slip Line Field Analysis.10.5 Formation of Aluminum Beverage Cans: Deep Drawing, Ironing, and Shaping.10.6 Forming and Rheology of Glasses and Polymers.10.7 Tape Casting of Ceramic Slurries.10.8 References.10.9 Problems.Index.
1,630 citations
TL;DR: Nanotubes derivatized with a 4-tert-butylbenzene moiety were found to possess significantly improved solubility in organic solvents and represents the marriage of wire-like nanotubes with molecular electronic devices.
Abstract: Small-diameter (ca. 0.7 nm) single-wall carbon nanotubes are predicted to display enhanced reactivity relative to larger-diameter nanotubes due to increased curvature strain. The derivatization of these small-diameter nanotubes via electrochemical reduction of a variety of aryl diazonium salts is described. The estimated degree of functionalization is as high as one out of every 20 carbons in the nanotubes bearing a functionalized moiety. The functionalizing moieties can be removed by heating in an argon atmosphere. Nanotubes derivatized with a 4-tert-butylbenzene moiety were found to possess significantly improved solubility in organic solvents. Functionalization of the nanotubes with a molecular system that has exhibited switching and memory behavior is shown. This represents the marriage of wire-like nanotubes with molecular electronic devices.
1,390 citations
1,192 citations
TL;DR: In this paper, a biomimetic artificial neuron was developed by extending the length of the sensor, which is a long continuous strain sensor that has a low cost, is simple to install and is lightweight.
Abstract: A carbon nanotube polymer material was used to form a piezoresistive strain sensor for structural health monitoring applications. The polymer improves the interfacial bonding between the nanotubes. Previous single walled carbon nanotube buckypaper sensors produced distorted strain measurements because the van der Waals attraction force allowed axial slipping of the smooth surfaces of the nanotubes. The polymer sensor uses larger multi-walled carbon nanotubes which improve the strain transfer, repeatability and linearity of the sensor. An electrical model of the nanotube strain sensor was derived based on electrochemical impedance spectroscopy and strain testing. The model is useful for designing nanotube sensor systems. A biomimetic artificial neuron was developed by extending the length of the sensor. The neuron is a long continuous strain sensor that has a low cost, is simple to install and is lightweight. The neuron has a low bandwidth and adequate strain sensitivity. The neuron sensor is particularly useful for detecting large strains and cracking, and can reduce the number of channels of data acquisition needed for the health monitoring of large structures.
973 citations
"Development and Characterization of..." refers background or methods in this paper
...CNT nanocomposites with biodegradable polymers (Mittal 2011) and SWNT/polymethylmethacrylate composite have been developed for strain sensing (Kang et al. 2006), MWNTs/glass fiber epoxy composite, (Yuezhen Bin et al. 2003) (Thostenson and Chou 2006) CNT/polyvinylidifluorid (PVDF) (J. M. Park et…...
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...(Kang et al. 2006) determined the dynamic response of 10% wt....
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...Kang et al. (Kang et al. 2006) determined the dynamic response of 10% wt. single walled CNT (SWNT) sheet nanocomposite sensor with polymethylmethacrylate (PMMA) matrix....
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...CNT nanocomposites with biodegradable polymers (Mittal 2011) and SWNT/polymethylmethacrylate composite have been developed for strain sensing (Kang et al. 2006), MWNTs/glass fiber epoxy composite, (Yuezhen Bin et al....
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...CNT nanocomposites with biodegradable polymers (Mittal 2011) and SWNT/polymethylmethacrylate composite have been developed for strain sensing (Kang et al. 2006), MWNTs/glass fiber epoxy composite, (Yuezhen Bin et al. 2003) (Thostenson and Chou 2006) CNT/polyvinylidifluorid (PVDF) (J. M. Park et al., 2013), CNT/poly(ionic liquid)s, (Gendron et al. 2015) composites have been prepared and shown to possess strain sensing capabilities....
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673 citations
"Development and Characterization of..." refers methods in this paper
...…composite have been developed for strain sensing (Kang et al. 2006), MWNTs/glass fiber epoxy composite, (Yuezhen Bin et al. 2003) (Thostenson and Chou 2006) CNT/polyvinylidifluorid (PVDF) (J. M. Park et al., 2013), CNT/poly(ionic liquid)s, (Gendron et al. 2015) composites have been prepared and…...
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