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Pratt B, Deora T, Mohren T, Daniel T. Neural evidence supports a dual sensory-motor role for insect wings. Proc Biol Sci 2018; 284:rspb.2017.0969. [PMID: 28904136 PMCID: PMC5597827 DOI: 10.1098/rspb.2017.0969] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/09/2017] [Indexed: 01/29/2023] Open
Abstract
Flying insects use feedback from various sensory modalities including vision and mechanosensation to navigate through their environment. The rapid speed of mechanosensory information acquisition and processing compensates for the slower processing times associated with vision, particularly under low light conditions. While halteres in dipteran species are well known to provide such information for flight control, less is understood about the mechanosensory roles of their evolutionary antecedent, wings. The features that wing mechanosensory neurons (campaniform sensilla) encode remains relatively unexplored. We hypothesized that the wing campaniform sensilla of the hawkmoth, Manduca sexta, rapidly and selectively extract mechanical stimulus features in a manner similar to halteres. We used electrophysiological and computational techniques to characterize the encoding properties of wing campaniform sensilla. To accomplish this, we developed a novel technique for localizing receptive fields using a focused IR laser that elicits changes in the neural activity of mechanoreceptors. We found that (i) most wing mechanosensors encoded mechanical stimulus features rapidly and precisely, (ii) they are selective for specific stimulus features, and (iii) there is diversity in the encoding properties of wing campaniform sensilla. We found that the encoding properties of wing campaniform sensilla are similar to those for haltere neurons. Therefore, it appears that the neural architecture that underlies the haltere sensory function is present in wings, which lends credence to the notion that wings themselves may serve a similar sensory function. Thus, wings may not only function as the primary actuator of the organism but also as sensors of the inertial dynamics of the animal.
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Affiliation(s)
- Brandon Pratt
- Department of Biology, University of Washington, Seattle, WA 98105, USA
| | - Tanvi Deora
- Department of Biology, University of Washington, Seattle, WA 98105, USA
| | - Thomas Mohren
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98105, USA
| | - Thomas Daniel
- Department of Biology, University of Washington, Seattle, WA 98105, USA
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Galao O, Baeza FJ, Zornoza E, Garcés P. Carbon Nanofiber Cement Sensors to Detect Strain and Damage of Concrete Specimens Under Compression. Nanomaterials (Basel) 2017; 7:E413. [PMID: 29186797 PMCID: PMC5746903 DOI: 10.3390/nano7120413] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/07/2017] [Accepted: 11/20/2017] [Indexed: 11/16/2022]
Abstract
Cement composites with nano-additions have been vastly studied for their functional applications, such as strain and damage sensing. The capacity of a carbon nanofiber (CNF) cement paste has already been tested. However, this study is focused on the use of CNF cement composites as sensors in regular concrete samples. Different measuring techniques and humidity conditions of CNF samples were tested to optimize the strain and damage sensing of this material. In the strain sensing tests (for compressive stresses up to 10 MPa), the response depends on the maximum stress applied. The material was more sensitive at higher loads. Furthermore, the actual load time history did not influence the electrical response, and similar curves were obtained for different test configurations. On the other hand, damage sensing tests proved the capability of CNF cement composites to measure the strain level of concrete samples, even for loads close to the material's strength. Some problems were detected in the strain transmission between sensor and concrete specimens, which will require specific calibration of each sensor one attached to the structure.
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Affiliation(s)
| | | | | | - Pedro Garcés
- Department of Civil Engineering, University of Alicante, 03690 San Vicente del Raspeig, Spain; (O.G.); (F.J.B.); (E.Z.)
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Liu YJ, Cao WT, Ma MG, Wan P. Ultrasensitive Wearable Soft Strain Sensors of Conductive, Self-healing, and Elastic Hydrogels with Synergistic "Soft and Hard" Hybrid Networks. ACS Appl Mater Interfaces 2017; 9:25559-25570. [PMID: 28696658 DOI: 10.1021/acsami.7b07639] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Robust, stretchable, and strain-sensitive hydrogels have recently attracted immense research interest because of their potential application in wearable strain sensors. The integration of the synergistic characteristics of decent mechanical properties, reliable self-healing capability, and high sensing sensitivity for fabricating conductive, elastic, self-healing, and strain-sensitive hydrogels is still a great challenge. Inspired by the mechanically excellent and self-healing biological soft tissues with hierarchical network structures, herein, functional network hydrogels are fabricated by the interconnection between a "soft" homogeneous polymer network and a "hard" dynamic ferric (Fe3+) cross-linked cellulose nanocrystals (CNCs-Fe3+) network. Under stress, the dynamic CNCs-Fe3+ coordination bonds act as sacrificial bonds to efficiently dissipate energy, while the homogeneous polymer network leads to a smooth stress-transfer, which enables the hydrogels to achieve unusual mechanical properties, such as excellent mechanical strength, robust toughness, and stretchability, as well as good self-recovery property. The hydrogels demonstrate autonomously self-healing capability in only 5 min without the need of any stimuli or healing agents, ascribing to the reorganization of CNCs and Fe3+ via ionic coordination. Furthermore, the resulted hydrogels display tunable electromechanical behavior with sensitive, stable, and repeatable variations in resistance upon mechanical deformations. Based on the tunable electromechanical behavior, the hydrogels can act as a wearable strain sensor to monitor finger joint motions, breathing, and even the slight blood pulse. This strategy of building synergistic "soft and hard" structures is successful to integrate the decent mechanical properties, reliable self-healing capability, and high sensing sensitivity together for assembling a high-performance, flexible, and wearable strain sensor.
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Affiliation(s)
- Yan-Jun Liu
- Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Key Laboratory of Lignocellulosic Chemistry, College of Materials Science and Technology, Beijing Forestry University , Beijing 100083, P.R. China
- Center of Advanced Elastomer Materials, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, P.R. China
| | - Wen-Tao Cao
- Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Key Laboratory of Lignocellulosic Chemistry, College of Materials Science and Technology, Beijing Forestry University , Beijing 100083, P.R. China
| | - Ming-Guo Ma
- Engineering Research Center of Forestry Biomass Materials and Bioenergy, Beijing Key Laboratory of Lignocellulosic Chemistry, College of Materials Science and Technology, Beijing Forestry University , Beijing 100083, P.R. China
- Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology , Jinan 250353, P.R. China
| | - Pengbo Wan
- Center of Advanced Elastomer Materials, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology , Beijing 100029, P.R. China
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54
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Yao S, Myers A, Malhotra A, Lin F, Bozkurt A, Muth JF, Zhu Y. A Wearable Hydration Sensor with Conformal Nanowire Electrodes. Adv Healthc Mater 2017; 6. [PMID: 28128888 DOI: 10.1002/adhm.201601159] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 12/09/2016] [Indexed: 11/07/2022]
Abstract
A wearable skin hydration sensor in the form of a capacitor is demonstrated based on skin impedance measurement. The capacitor consists of two interdigitated or parallel electrodes that are made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. The flexible and stretchable nature of the AgNW/PDMS electrode allows conformal contact to the skin. The hydration sensor is insensitive to the external humidity change and is calibrated against a commercial skin hydration system on an artificial skin over a wide hydration range. The hydration sensor is packaged into a flexible wristband, together with a network analyzer chip, a button cell battery, and an ultralow power microprocessor with Bluetooth. In addition, a chest patch consisting of a strain sensor, three electrocardiography electrodes, and a skin hydration sensor is developed for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless, and continuous monitoring of skin hydration and other health parameters.
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Affiliation(s)
- Shanshan Yao
- Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh NC 27695 USA
| | - Amanda Myers
- Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh NC 27695 USA
| | - Abhishek Malhotra
- Department of Electrical and Computer Engineering North Carolina State University Raleigh NC 27695 USA
| | - Feiyan Lin
- Department of Electrical and Computer Engineering North Carolina State University Raleigh NC 27695 USA
| | - Alper Bozkurt
- Department of Electrical and Computer Engineering North Carolina State University Raleigh NC 27695 USA
| | - John F. Muth
- Department of Electrical and Computer Engineering North Carolina State University Raleigh NC 27695 USA
| | - Yong Zhu
- Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh NC 27695 USA
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Bremer K, Weigand F, Zheng Y, Alwis LS, Helbig R, Roth B. Structural Health Monitoring Using Textile Reinforcement Structures with Integrated Optical Fiber Sensors. Sensors (Basel) 2017; 17:s17020345. [PMID: 28208636 PMCID: PMC5336015 DOI: 10.3390/s17020345] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 02/04/2017] [Indexed: 12/02/2022]
Abstract
Optical fiber-based sensors “embedded” in functionalized carbon structures (FCSs) and textile net structures (TNSs) based on alkaline-resistant glass are introduced for the purpose of structural health monitoring (SHM) of concrete-based structures. The design aims to monitor common SHM parameters such as strain and cracks while at the same time acting as a structural strengthening mechanism. The sensor performances of the two systems are characterized in situ using Mach-Zehnder interferometric (MZI) and optical attenuation measurement techniques, respectively. For this purpose, different FCS samples were subjected to varying elongation using a tensile testing machine by carefully incrementing the applied force, and good correlation between the applied force and measured length change was observed. For crack detection, the functionalized TNSs were embedded into a concrete block which was then exposed to varying load using the three-point flexural test until destruction. Promising results were observed, identifying that the location of the crack can be determined using the conventional optical time domain reflectometry (OTDR) technique. The embedded sensors thus evaluated show the value of the dual achievement of the schemes proposed in obtaining strain/crack measurement while being utilized as strengthening agents as well.
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Affiliation(s)
- Kort Bremer
- Hannover Centre for Optical Technologies (HOT), Leibniz University Hannover, Hannover 30167, Germany.
| | - Frank Weigand
- Saxon Textile Research Institute (STFI), Chemnitz 09125, Germany.
| | - Yulong Zheng
- Hannover Centre for Optical Technologies (HOT), Leibniz University Hannover, Hannover 30167, Germany.
| | - Lourdes Shanika Alwis
- School of Engineering and the Built Environment, Edinburgh Napier University, Edinburgh EH10 5DT, UK.
| | - Reinhard Helbig
- Saxon Textile Research Institute (STFI), Chemnitz 09125, Germany.
| | - Bernhard Roth
- Hannover Centre for Optical Technologies (HOT), Leibniz University Hannover, Hannover 30167, Germany.
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56
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Natarajan TS, Eshwaran SB, Stöckelhuber KW, Wießner S, Pötschke P, Heinrich G, Das A. Strong Strain Sensing Performance of Natural Rubber Nanocomposites. ACS Appl Mater Interfaces 2017; 9:4860-4872. [PMID: 28094912 DOI: 10.1021/acsami.6b13074] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A detail study concerning the strain (tensile) dependent electrical conductivity of elastomeric composites is reported in this present paper. Multiwall carbon nanotubes (CNT), conducting carbon black (CB), and their combinations were considered as conducting filler in cross-linked natural rubber matrix. The loadings of the fillers were considered from 3 to 11 phr (filler concentration close to their percolation threshold). Without hindering the elastic nature of the composite (reversible stretchability up to several 100%), the change of relative resistance, ΔR/R0 (ΔR is the change in the resistance with respect to strain and R0 is the initial resistance of the sample) of the CB filled composites was found to be as much as ∼1300 at around 120% elongation. This value is much higher than any other reported values obtained from conducting polymeric composites. It was found that CNT offered a strong strain dependent character in the regime 100% to 150% elongation, whereas, the carbon black filled natural rubber showed strong strain dependencies at 50% to 100% elongation strain. The combination of two different fillers could be exploited to tailor and manipulate the sensing operating regime from 50% to 150% strain depending on the ratios of the two filler system. Additionally, after several loading-unloading cycles, the conductivity of the sample was very stable for CB filled system but for CNT filled system the conductivity of the sample was altered. This type of elastic materials could be used in structural health monitoring, sensors in different dynamic elastomeric parts like tires, valves, gaskets, engine mounts, etc.
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Affiliation(s)
- Tamil Selvan Natarajan
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
- Technische Universität Dresden, Institut für Werkstoffwissenschaft , D-01062 Dresden, Germany
| | - Subramani Bhagavatheswaran Eshwaran
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
- Technische Universität Dresden, Institut für Werkstoffwissenschaft , D-01062 Dresden, Germany
| | | | - Sven Wießner
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
- Technische Universität Dresden, Institut für Werkstoffwissenschaft , D-01062 Dresden, Germany
| | - Petra Pötschke
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
| | - Gert Heinrich
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
- Technische Universität Dresden, Institut für Werkstoffwissenschaft , D-01062 Dresden, Germany
| | - Amit Das
- Leibniz-Institut für Polymerforschung Dresden e.V. , Hohe Strasse 6, D-01069 Dresden, Germany
- Tampere University of Technology , Korkeakoulunkatu 16, Fi-33720 Tampere, Finland
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57
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Guo J, Liu X, Jiang N, Yetisen AK, Yuk H, Yang C, Khademhosseini A, Zhao X, Yun SH. Highly Stretchable, Strain Sensing Hydrogel Optical Fibers. Adv Mater 2016; 28:10244-10249. [PMID: 27714887 PMCID: PMC5148684 DOI: 10.1002/adma.201603160] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/14/2016] [Indexed: 05/17/2023]
Abstract
A core-clad fiber made of elastic, tough hydrogels is highly stretchable while guiding light. Fluorescent dyes are easily doped into the hydrogel fiber by diffusion. When stretched, the transmission spectrum of the fiber is altered, enabling the strain to be measured and also its location.
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Affiliation(s)
- Jingjing Guo
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139, USA. State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China
| | - Xinyue Liu
- Soft Active Materials Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Nan Jiang
- Biomaterials Innovation Research Center, Engineering in Medicine Division, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts, 02139, USA. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122, Luoshi Road, Wuhan, 430070, China
| | - Ali K. Yetisen
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139, USA
| | - Hyunwoo Yuk
- Soft Active Materials Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Changxi Yang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China
| | - Ali Khademhosseini
- Biomaterials Innovation Research Center, Engineering in Medicine Division, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts, 02139, USA
| | - Xuanhe Zhao
- Soft Active Materials Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139, USA
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58
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Lin Y, Dong X, Liu S, Chen S, Wei Y, Liu L. Graphene-Elastomer Composites with Segregated Nanostructured Network for Liquid and Strain Sensing Application. ACS Appl Mater Interfaces 2016; 8:24143-24151. [PMID: 27552175 DOI: 10.1021/acsami.6b08587] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
One of the critical issues for the fabrication of desirable sensing materials has focused on the construction of an effective continuous network with a low percolation threshold. Herein, graphene-based elastomer composites with a segregated nanostructured graphene network were prepared by a novel and effective ice-templating strategy. The segregated graphene network bestowed on the natural rubber (NR) composites an ultralow electrical percolation threshold (0.4 vol %), 8-fold lower than that of the NR/graphene composites with homogeneous dispersion morphology (3.6 vol %). The resulting composites containing 0.63 vol % graphene exhibited high liquid sensing responsivity (6700), low response time (114 s), and good reproducibility. The unique segregated structure also provides this graphene-based elastomer (containing 0.42 vol % graphene) with exceptionally high stretchability, sensitivity (gauge factor ≈ 139), and good reproducibility (∼400 cycles) of up to 60% strain under cyclic tests. The fascinating performances highlight the potential applications of graphene-elastomer composites with an effective segregated network as multifunctional sensing materials.
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Affiliation(s)
- Yong Lin
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
| | - Xuchu Dong
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
| | - Shuqi Liu
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
| | - Song Chen
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
| | - Yong Wei
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
| | - Lan Liu
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology , Guangzhou 510640, P. R. China
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59
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Bonnesoeur V, Constant T, Moulia B, Fournier M. Forest trees filter chronic wind-signals to acclimate to high winds. New Phytol 2016; 210:850-860. [PMID: 26790391 DOI: 10.1111/nph.13836] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
Controlled experiments have shown that trees acclimate thigmomorphogenetically to wind-loads by sensing their deformation (strain). However, the strain regime in nature is exposed to a full spectrum of winds. We hypothesized that trees avoid overreacting by responding only to winds which bring information on local climate and/or wind exposure. Additionally, competition for light dependent on tree social status also likely affects thigmomorphogenesis. We monitored and manipulated quantitatively the strain regimes of 15 pairs of beech (Fagus sylvatica) trees of contrasting social status in an acclimated stand, and quantified the effects of these regimes on the radial growth over a vegetative season. Trees exposed to artificial bending, the intensity of which corresponds to the strongest wind-induced strains, enhanced their secondary growth by at least 80%. Surprisingly, this reaction was even greater - relatively - for suppressed trees than for dominant ones. Acclimated trees did not sense the different types of wind events in the same way. Daily wind speed peaks due to thermal winds were filtered out. Thigmomorphogenesis was therefore driven by intense storms. Thigmomorphogenesis is also likely to be involved in determining social status.
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Affiliation(s)
- Vivien Bonnesoeur
- UMR 1092 LERFOB, INRA, Champenoux, 54280, France
- UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France
| | - Thiéry Constant
- UMR 1092 LERFOB, INRA, Champenoux, 54280, France
- UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France
| | - Bruno Moulia
- UMR 547 PIAF, Clermont Université, Université Blaise Pascal, BP 10448, Clermont-Ferrand, 63000, France
- UMR 547 PIAF, INRA, Clermont-Ferrand, 63100, France
| | - Meriem Fournier
- UMR 1092 LERFOB, INRA, Champenoux, 54280, France
- UMR 1092 LERFOB, AgroParisTech, Nancy, 54000, France
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60
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Goeckner K, Pepakayala V, Nervina J, Gianchandani Y, Kapila S. Three-Dimensional Force Measurements During Rapid Palatal Expansion in Sus scrofa. Micromachines (Basel) 2016; 7:E64. [PMID: 30407437 PMCID: PMC6189903 DOI: 10.3390/mi7040064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/16/2016] [Accepted: 04/06/2016] [Indexed: 11/16/2022]
Abstract
Rapid palatal expansion is an orthodontic procedure widely used to correct the maxillary arch. However, its outcome is significantly influenced by factors that show a high degree of variability amongst patients. The traditional treatment methodology is based on an intuitive and heuristic treatment approach because the forces applied in the three dimensions are indeterminate. To enable optimal and individualized treatment, it is essential to measure the three-dimensional (3D) forces and displacements created by the expander. This paper proposes a method for performing these 3D measurements using a single embedded strain sensor, combining experimental measurements of strain in the palatal expander with 3D finite element analysis (FEA). The method is demonstrated using the maxillary jaw from a freshly euthanized pig (Sus scrofa) and a hyrax-design rapid palatal expander (RPE) appliance with integrated strain gage. The strain gage measurements are recorded using a computer interface, following which the expansion forces and extent of expansion are estimated by FEA. A total activation of 2.0 mm results in peak total force of about 100 N-almost entirely along the direction of expansion. The results also indicate that more than 85% of the input activation is immediately transferred to the palate and/or teeth. These studies demonstrate a method for assessing and individualizing expansion magnitudes and forces during orthopedic expansion of the maxilla. This provides the basis for further development of smart orthodontic appliances that provide real-time readouts of forces and movements, which will allow personalized, optimal treatment.
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Affiliation(s)
- Kelly Goeckner
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Venkatram Pepakayala
- Center for Wireless Integrated MicroSensing and Systems, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Jeanne Nervina
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Yogesh Gianchandani
- Center for Wireless Integrated MicroSensing and Systems, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Sunil Kapila
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA.
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61
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Paek J, Li Q, Cho IH, Kim J. Minimally Intrusive Optical Micro- Strain Sensing in Bulk Elastomer Using Embedded Fabry-Pérot Etalon. Micromachines (Basel) 2016; 7:mi7040061. [PMID: 30407434 PMCID: PMC6190261 DOI: 10.3390/mi7040061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/29/2016] [Accepted: 04/04/2016] [Indexed: 11/29/2022]
Abstract
A variety of strain sensors have been developed to measure internal deformations of elastomeric structures. Strain sensors measuring extremely small mechanical strain, however, have not yet been reported due mainly to the inherently intrusive integration of the sensor with the test structure. In this work, we report the development of a minimally intrusive, highly sensitive mechanical strain transducer realized by monolithically embedding a Fabry-Pérot (FP) etalon into a poly(dimethylsiloxane) (PDMS) block test structure. Due to the extreme sensitivity of the FP resonance condition to the thickness of the spacer layer between the two reflectors, the limit of detection in the mechanical deformation can be as low as ~110 nm with a 632.8 nm laser used as the probing light. The compatibility of PDMS with additive fabrication turned out to be the most crucial enabling factor in the realization of the FP etalon-based strain transducer.
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Affiliation(s)
- Jungwook Paek
- Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
| | - Qiang Li
- Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
| | - In Ho Cho
- Department of Civil, Construction & Environmental Engineering, Iowa State University, Ames, IA 50011, USA.
| | - Jaeyoun Kim
- Department of Electrical & Computer Engineering, Iowa State University, Ames, IA 50011, USA.
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62
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Eberle AL, Dickerson BH, Reinhall PG, Daniel TL. A new twist on gyroscopic sensing: body rotations lead to torsion in flapping, flexing insect wings. J R Soc Interface 2015; 12:20141088. [PMID: 25631565 DOI: 10.1098/rsif.2014.1088] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Insects perform fast rotational manoeuvres during flight. While two insect orders use flapping halteres (specialized organs evolved from wings) to detect body dynamics, it is unknown how other insects detect rotational motions. Like halteres, insect wings experience gyroscopic forces when they are flapped and rotated and recent evidence suggests that wings might indeed mediate reflexes to body rotations. But, can gyroscopic forces be detected using only changes in the structural dynamics of a flapping, flexing insect wing? We built computational and robotic models to rotate a flapping wing about an axis orthogonal to flapping. We recorded high-speed video of the model wing, which had a flexural stiffness similar to the wing of the Manduca sexta hawkmoth, while flapping it at the wingbeat frequency of Manduca (25 Hz). We compared the three-dimensional structural dynamics of the wing with and without a 3 Hz, 10° rotation about the yaw axis. Our computational model revealed that body rotation induces a new dynamic mode: torsion. We verified our result by measuring wing tip displacement, shear strain and normal strain of the robotic wing. The strains we observed could stimulate an insect's mechanoreceptors and trigger reflexive responses to body rotations.
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Affiliation(s)
- A L Eberle
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195, USA
| | - B H Dickerson
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - P G Reinhall
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195, USA
| | - T L Daniel
- Department of Biology, University of Washington, Seattle, WA 98195, USA
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Iadicicco A, Campopiano S. Sensing features of long period gratings in hollow core fibers. Sensors (Basel) 2015; 15:8009-19. [PMID: 25855037 PMCID: PMC4431214 DOI: 10.3390/s150408009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 11/16/2022]
Abstract
We report on the investigation of the sensing features of the Long-Period fiber Gratings (LPGs) fabricated in hollow core photonic crystal fibers (HC-PCFs) by the pressure assisted Electric Arc Discharge (EAD) technique. In particular, the characterization of the LPG in terms of shift in resonant wavelengths and changes in attenuation band depth to the environmental parameters: strain, temperature, curvature, refractive index and pressure is presented. The achieved results show that LPGs in HC-PCFs represent a novel high performance sensing platform for measurements of different physical parameters including strain, temperature and, especially, for measurements of environmental pressure. The pressure sensitivity enhancement is about four times greater if we compare LPGs in HC and standard fibers. Moreover, differently from LPGs in standard fibers, these LPGs realized in innovative fibers, i.e., the HC-PCFs, are not sensitive to surrounding refractive index.
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Affiliation(s)
- Agostino Iadicicco
- Engineering Department, University of Naples "Parthenope", Centro Direzionale Isola C4, 80143 Napoli, Italy.
| | - Stefania Campopiano
- Engineering Department, University of Naples "Parthenope", Centro Direzionale Isola C4, 80143 Napoli, Italy.
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64
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Abstract
The complex structure of the macroscopic assemblies of carbon nanotubes and variable intrinsic piezoresistivity of nanotubes themselves lead to highly interesting piezoresistive performance of this new type of conductive material. Here, we present an in-depth study of the piezoresistive effect in carbon nanotube fibers, i.e., yarnlike assemblies made purely of aligned carbon nanotubes, which are expected to find applications as electrical and electronic materials. The resistivity changes of carbon nanotube fibers were measured on initial loading, through the elastic/plastic transition, on cyclic loading and on stress relaxation. The various regimes of stress/strain behavior were modeled using a standard linear solid model, which was modified with an additional element in series to account for the observed creep behavior. On the basis of the experimental and modeling results, the origin of piezoresistivity is discussed. An additional effect on the resistivity was found as the fiber was held under load which led to observations of the effect of humidity and the associated water adsorption level on the resistivity. We show that the equilibrium uptake of moisture leads to the decrease in gauge factor of the fiber decrease, i.e., the reduction in the sensitivity of fiber resistivity to loading.
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Affiliation(s)
- Agnieszka Lekawa-Raus
- Department of Materials Science and Metallurgy, University of Cambridge , Cambridge CB3 0FS, U.K
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65
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Vilaplana JL, Baeza FJ, Galao O, Zornoza E, Garcés P. Self-Sensing Properties of Alkali Activated Blast Furnace Slag (BFS) Composites Reinforced with Carbon Fibers. Materials (Basel) 2013; 6:4776-86. [PMID: 28788359 DOI: 10.3390/ma6104776] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 09/24/2013] [Accepted: 10/17/2013] [Indexed: 11/16/2022]
Abstract
In recent years, several researchers have shown the good performance of alkali activated slag cement and concretes. Besides their good mechanical properties and durability, this type of cement is a good alternative to Portland cements if sustainability is considered. Moreover, multifunctional cement composites have been developed in the last decades for their functional applications (self-sensing, EMI shielding, self-heating, etc.). In this study, the strain and damage sensing possible application of carbon fiber reinforced alkali activated slag pastes has been evaluated. Cement pastes with 0, 0.29 and 0.58 vol % carbon fiber addition were prepared. Both carbon fiber dosages showed sensing properties. For strain sensing, function gage factors of up to 661 were calculated for compressive cycles. Furthermore, all composites with carbon fibers suffered a sudden increase in their resistivity when internal damages began, prior to any external signal of damage. Hence, this material may be suitable as strain or damage sensor.
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66
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Choi SW, Kwon E, Kim Y, Hong K, Park HS. A practical data recovery technique for long-term strain monitoring of mega columns during construction. Sensors (Basel) 2013; 13:10931-43. [PMID: 23966189 PMCID: PMC3812635 DOI: 10.3390/s130810931] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 08/12/2013] [Accepted: 08/16/2013] [Indexed: 11/17/2022]
Abstract
A practical data recovery method is proposed for the strain data lost during the safety monitoring of mega columns. The analytical relations among the measured strains are derived to recover the data lost due to unexpected errors in long-term measurement during construction. The proposed technique is applied to recovery of axial strain data of a mega column in an irregular building structure during construction. The axial strain monitoring using the wireless strain sensing system was carried out for one year and five months between 23 July 2010 and 22 February 2012. During the long-term strain sensing, three different types of measurement errors occurred. Using the recovery technique, the strain data that could not be measured at different intervals in the measurement were successfully recovered. It is confirmed that the problems that may occur during long-term wireless strain sensing of mega columns during construction could be resolved through the proposed recovery method.
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Affiliation(s)
- Se Woon Choi
- Department of Architectural Engineering, Yonsei University, Seoul 110-732, Korea.
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67
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Hong K, Lee J, Choi SW, Kim Y, Park HS. A strain-based load identification model for beams in building structures. Sensors (Basel) 2013; 13:9909-9920. [PMID: 23921825 PMCID: PMC3812586 DOI: 10.3390/s130809909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 07/31/2013] [Accepted: 07/31/2013] [Indexed: 06/02/2023]
Abstract
A strain-based load identification model for beam structures subjected to multiple loads is presented. The number of sensors for the load identification model is the same as the number of load conditions acting on a beam structure. In the model, the contribution of each load to the strains measured by strain sensors is defined. In this paper, the longitudinal strains measured from multiplexed fiber Bragg grating (FBG) strain sensors are used in the load identification. To avoid the dependency on the selection of locations for FBG sensors installed on a beam structure, the measured strain is expressed by a general form of a strain sensing model defined by superimposing the distribution shapes for strains from multiple loads. Numerical simulation is conducted to verify the model. Then, the load identification model is applied to monitoring of applied loads on a 4 m-long steel beam subjected to two concentrated loads. In the experiment, seven FBG sensors and nine electrical strain gages (ESGs) were installed on the surface of the bottom flange. The experimental results indicate a good agreement between estimated loadings from the model and the loads applied by a hydraulic jack.
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Affiliation(s)
- Kappyo Hong
- Department of Architectural Engineering, Yonsei University, Seoul, Korea.
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68
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Baeza FJ, Galao O, Zornoza E, Garcés P. Multifunctional Cement Composites Strain and Damage Sensors Applied on Reinforced Concrete (RC) Structural Elements. Materials (Basel) 2013; 6:841-55. [PMID: 28809343 DOI: 10.3390/ma6030841] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 11/17/2022]
Abstract
In this research, strain-sensing and damage-sensing functional properties of cement composites have been studied on a conventional reinforced concrete (RC) beam. Carbon nanofiber (CNFCC) and fiber (CFCC) cement composites were used as sensors on a 4 m long RC beam. Different casting conditions (in situ or attached), service location (under tension or compression) and electrical contacts (embedded or superficial) were compared. Both CNFCC and CFCC were suitable as strain sensors in reversible (elastic) sensing condition testing. CNFCC showed higher sensitivities (gage factor up to 191.8), while CFCC only reached gage factors values of 178.9 (tension) or 49.5 (compression). Furthermore, damage-sensing tests were run, increasing the applied load progressively up to the RC beam failure. In these conditions, CNFCC sensors were also strain sensitive, but no damage sensing mechanism was detected for the strain levels achieved during the tests. Hence, these cement composites could act as strain sensors, even for severe damaged structures near to their collapse.
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69
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Huth M, Porrati F, Schwalb C, Winhold M, Sachser R, Dukic M, Adams J, Fantner G. Focused electron beam induced deposition: A perspective. Beilstein J Nanotechnol 2012; 3:597-619. [PMID: 23019557 PMCID: PMC3458607 DOI: 10.3762/bjnano.3.70] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/19/2012] [Indexed: 05/19/2023]
Abstract
BACKGROUND Focused electron beam induced deposition (FEBID) is a direct-writing technique with nanometer resolution, which has received strongly increasing attention within the last decade. In FEBID a precursor previously adsorbed on a substrate surface is dissociated in the focus of an electron beam. After 20 years of continuous development FEBID has reached a stage at which this technique is now particularly attractive for several areas in both, basic and applied research. The present topical review addresses selected examples that highlight this development in the areas of charge-transport regimes in nanogranular metals close to an insulator-to-metal transition, the use of these materials for strain- and magnetic-field sensing, and the prospect of extending FEBID to multicomponent systems, such as binary alloys and intermetallic compounds with cooperative ground states. RESULTS After a brief introduction to the technique, recent work concerning FEBID of Pt-Si alloys and (hard-magnetic) Co-Pt intermetallic compounds on the nanometer scale is reviewed. The growth process in the presence of two precursors, whose flux is independently controlled, is analyzed within a continuum model of FEBID that employs rate equations. Predictions are made for the tunability of the composition of the Co-Pt system by simply changing the dwell time of the electron beam during the writing process. The charge-transport regimes of nanogranular metals are reviewed next with a focus on recent theoretical advancements in the field. As a case study the transport properties of Pt-C nanogranular FEBID structures are discussed. It is shown that by means of a post-growth electron-irradiation treatment the electronic intergrain-coupling strength can be continuously tuned over a wide range. This provides unique access to the transport properties of this material close to the insulator-to-metal transition. In the last part of the review, recent developments in mechanical strain-sensing and the detection of small, inhomogeneous magnetic fields by employing nanogranular FEBID structures are highlighted. CONCLUSION FEBID has now reached a state of maturity that allows a shift of the focus towards the development of new application fields, be it in basic research or applied. This is shown for selected examples in the present review. At the same time, when seen from a broader perspective, FEBID still has to live up to the original idea of providing a tool for electron-controlled chemistry on the nanometer scale. This has to be understood in the sense that, by providing a suitable environment during the FEBID process, the outcome of the electron-induced reactions can be steered in a controlled way towards yielding the desired composition of the products. The development of a FEBID-specialized surface chemistry is mostly still in its infancy. Next to application development, it is this aspect that will likely be a guiding light for the future development of the field of focused electron beam induced deposition.
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Affiliation(s)
- Michael Huth
- Physikalisches Institut, Max-von-Laue-Str. 1, Goethe-Universität, 60438 Frankfurt am Main, Germany
| | - Fabrizio Porrati
- Physikalisches Institut, Max-von-Laue-Str. 1, Goethe-Universität, 60438 Frankfurt am Main, Germany
| | - Christian Schwalb
- Physikalisches Institut, Max-von-Laue-Str. 1, Goethe-Universität, 60438 Frankfurt am Main, Germany
| | - Marcel Winhold
- Physikalisches Institut, Max-von-Laue-Str. 1, Goethe-Universität, 60438 Frankfurt am Main, Germany
| | - Roland Sachser
- Physikalisches Institut, Max-von-Laue-Str. 1, Goethe-Universität, 60438 Frankfurt am Main, Germany
| | - Maja Dukic
- Institute of Bioengineering, EPFL, STI IBI-STI LBNI, BM 3109 (Bâtiment BM), Station 17, CH-1015 Lausanne, Switzerland
| | - Jonathan Adams
- Institute of Bioengineering, EPFL, STI IBI-STI LBNI, BM 3109 (Bâtiment BM), Station 17, CH-1015 Lausanne, Switzerland
| | - Georg Fantner
- Institute of Bioengineering, EPFL, STI IBI-STI LBNI, BM 3109 (Bâtiment BM), Station 17, CH-1015 Lausanne, Switzerland
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