Wojciech Trubulec, R. Radecki, M. Osika, A. Ziaja-Sujdak, W. Staszewski
Recent years have brought more attention to new damage detection approaches based on nonlinear phenomena associated with Shear Horizontal (SH) waves. Many nonlinear effects–previously observed in ultrasonic wave propagation–have been considered for structural damage detection. The major effort has been put on classical nonlinear effects, such as higher harmonic generation. More recently, nonlinear vibro-acoustic modulation and modulation transfer mechanisms have been also observed in SH wave propagation. However, these phenomena have not been used for structural damage detection. The paper attempts to fulfill this gap. The proposed method involves two excitation waves. The low-frequency pumping wave is used for damage perturbation. In addition, high-frequency SH wave is used as a probing wave. The probing wave is modulated by the pumping wave in the presence of structural damage. The method is used in the paper for fatigue crack detection in metallic structural components. The results demonstrate that the proposed approach has a potential for structural damage detection. Previous research work demonstrates that classical nonlinear effects (e.g., higher harmonic generation) observed in SH waves offer better sensitivity to material microdefects than similar effects observed in longitudinal wave propagation. Therefore, it is anticipated that non-classical nonlinear affects associated with SH wave propagation will show similar potential. However, more research work is needed to confirm this assumption.
{"title":"Structural damage detection based on nonlinear vibro-acoustic modulations observed in shear horizontal wave propagation","authors":"Wojciech Trubulec, R. Radecki, M. Osika, A. Ziaja-Sujdak, W. Staszewski","doi":"10.1117/12.2658450","DOIUrl":"https://doi.org/10.1117/12.2658450","url":null,"abstract":"Recent years have brought more attention to new damage detection approaches based on nonlinear phenomena associated with Shear Horizontal (SH) waves. Many nonlinear effects–previously observed in ultrasonic wave propagation–have been considered for structural damage detection. The major effort has been put on classical nonlinear effects, such as higher harmonic generation. More recently, nonlinear vibro-acoustic modulation and modulation transfer mechanisms have been also observed in SH wave propagation. However, these phenomena have not been used for structural damage detection. The paper attempts to fulfill this gap. The proposed method involves two excitation waves. The low-frequency pumping wave is used for damage perturbation. In addition, high-frequency SH wave is used as a probing wave. The probing wave is modulated by the pumping wave in the presence of structural damage. The method is used in the paper for fatigue crack detection in metallic structural components. The results demonstrate that the proposed approach has a potential for structural damage detection. Previous research work demonstrates that classical nonlinear effects (e.g., higher harmonic generation) observed in SH waves offer better sensitivity to material microdefects than similar effects observed in longitudinal wave propagation. Therefore, it is anticipated that non-classical nonlinear affects associated with SH wave propagation will show similar potential. However, more research work is needed to confirm this assumption.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"41 1","pages":"124880M - 124880M-7"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80561299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents an experimental investigation on the origami patterned cylinder made of Tachi-Miura Polyhedron (TMP) unit cell. The unit cell shows strain-softening behavior under compression load. To analyze the effect of nonlinear behavior on the elastic wave propagation in TMP cylinder, fabrication of metallic origami cylinder and impact test were conducted. The thin metallic structure was fabricated using the vacuum bag method. The pressure was applied evenly to the aluminum facets, which have compliant hinges that behave like torsional springs. The first unit cell of the cylinder structure was connected to the dynamic shaker and the pulse load was applied. To measure the dynamic behavior of unit cells during elastic wave propagation, the stereo pattern recognition (SPR) camera system was employed. The experimental result shows that the compressive wave, induced by impact load, was attenuated due to the nonlinear characteristics of the TMP unit cell. Furthermore, the tensile wave, which emerged later, arrived first on the last unit cell. It means that the tensile wave overtook the compressive wave. The speed of the elastic wave is affected by the stiffness of the structure. Based on the strain-softening behavior of the TMP unit cell, the compressive wave is slower than the tensile wave. It induced the attenuation of compressive impact and overtaking of tensile elastic wave. We can expect that this nonlinear characteristic of the origami-based structure can be applied to the shock mitigation structure.
{"title":"Experimental analysis on nonlinear elastic wave characteristics of metallic origami cylinder","authors":"H. Park, J. H. Han, Jinkyu Yang","doi":"10.1117/12.2658272","DOIUrl":"https://doi.org/10.1117/12.2658272","url":null,"abstract":"This paper presents an experimental investigation on the origami patterned cylinder made of Tachi-Miura Polyhedron (TMP) unit cell. The unit cell shows strain-softening behavior under compression load. To analyze the effect of nonlinear behavior on the elastic wave propagation in TMP cylinder, fabrication of metallic origami cylinder and impact test were conducted. The thin metallic structure was fabricated using the vacuum bag method. The pressure was applied evenly to the aluminum facets, which have compliant hinges that behave like torsional springs. The first unit cell of the cylinder structure was connected to the dynamic shaker and the pulse load was applied. To measure the dynamic behavior of unit cells during elastic wave propagation, the stereo pattern recognition (SPR) camera system was employed. The experimental result shows that the compressive wave, induced by impact load, was attenuated due to the nonlinear characteristics of the TMP unit cell. Furthermore, the tensile wave, which emerged later, arrived first on the last unit cell. It means that the tensile wave overtook the compressive wave. The speed of the elastic wave is affected by the stiffness of the structure. Based on the strain-softening behavior of the TMP unit cell, the compressive wave is slower than the tensile wave. It induced the attenuation of compressive impact and overtaking of tensile elastic wave. We can expect that this nonlinear characteristic of the origami-based structure can be applied to the shock mitigation structure.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"42 1","pages":"1248303 - 1248303-6"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75884325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces an ultrasonic piezoelectric transducer consisted of a concave shaped piezoelectric film and a support with an air cavity for vibration. The high flexibility and sensitivity of the transducer are guaranteed by utilization of Polyvinylidene fluoride (PVDF), and these are important in designing transducers of good acoustic performance. Ultrasound pressure results of the transducer are measured from frequency sweep inputs. From the results, we observe that the concave case generates several resonant peaks within a specific frequency range. Additionally, the sound pressure change of the transducers with different radii of curvature is investigated. The experimental results demonstrate that radius of curvature contributes to the sound pressure magnitude significantly.
{"title":"Ultrasonic piezoelectric transducer design with concave surface","authors":"C. Lim, Youngsu Cha","doi":"10.1117/12.2657014","DOIUrl":"https://doi.org/10.1117/12.2657014","url":null,"abstract":"This paper introduces an ultrasonic piezoelectric transducer consisted of a concave shaped piezoelectric film and a support with an air cavity for vibration. The high flexibility and sensitivity of the transducer are guaranteed by utilization of Polyvinylidene fluoride (PVDF), and these are important in designing transducers of good acoustic performance. Ultrasound pressure results of the transducer are measured from frequency sweep inputs. From the results, we observe that the concave case generates several resonant peaks within a specific frequency range. Additionally, the sound pressure change of the transducers with different radii of curvature is investigated. The experimental results demonstrate that radius of curvature contributes to the sound pressure magnitude significantly.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"1 1","pages":"124830G - 124830G-6"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74420458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Highly anisotropic, fiber-based structures are a successful concept in nature. Usual dielectric elastomer actuators are entirely soft and rely on the integration of stiff carrier frames for the fragile dielectric membranes. Within this work, a completely soft, fiber-reinforced free-standing tubular actuator concept is presented. The circumferentially running carbon fibers are integrated into the inner electrode of the DEA and stabilize the cross-section, while having negligible impact on the mechanical stiffness in the axial direction. Through the segmentation of the outer electrode of the actuator, active bending in the corresponding directions is achieved. Moreover, if all segments are activated simultaneously, the actuator expands axially. The presented manufacturing approach allows for the adjustment of the dimensions over a wide range of diameters and lengths. Furthermore, the local stiffness of actuators can be tailored by varying the amount of fibers incorporated into the electrode. The electroactive deformation of actuators with different diameter-to-length ratios and fiber densities is investigated.
{"title":"Free-standing tubular DEAs for multi-directional bending","authors":"Markus Koenigsdorff, J. Mersch, G. Gerlach","doi":"10.1117/12.2657028","DOIUrl":"https://doi.org/10.1117/12.2657028","url":null,"abstract":"Highly anisotropic, fiber-based structures are a successful concept in nature. Usual dielectric elastomer actuators are entirely soft and rely on the integration of stiff carrier frames for the fragile dielectric membranes. Within this work, a completely soft, fiber-reinforced free-standing tubular actuator concept is presented. The circumferentially running carbon fibers are integrated into the inner electrode of the DEA and stabilize the cross-section, while having negligible impact on the mechanical stiffness in the axial direction. Through the segmentation of the outer electrode of the actuator, active bending in the corresponding directions is achieved. Moreover, if all segments are activated simultaneously, the actuator expands axially. The presented manufacturing approach allows for the adjustment of the dimensions over a wide range of diameters and lengths. Furthermore, the local stiffness of actuators can be tailored by varying the amount of fibers incorporated into the electrode. The electroactive deformation of actuators with different diameter-to-length ratios and fiber densities is investigated.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"55 1","pages":"124820N - 124820N-8"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74122726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Small-scale magnetoactive soft robots (MSRs) with multimodal locomotion and wireless actuation capabilities have emerged in recent years for various highly sensitive and precise biomedical tasks such as targeted drug delivery and minimally invasive therapies. MSRs comprise magnetoactive elastomers consisting of micron-sized hard magnetic particles, such as neodymium-iron-boron (NdFeB), suspended or arranged into an elastomeric matrix. These robots generally exhibit large deformation under an applied magnetics stimulus, which is considered favorable for the aforementioned applications. Only limited efforts, however, have been reported on characterization of such robots. This is likely due to their nonlinear dynamics, especially under large deformations and hysteretic stress-strain characteristics, which strongly depend on the magnitude and frequency of the external magnetic stimuli. This study experimentally investigated and analyzed the real-time nonlinear and hysteretic responses of a MSR fabricated in the form of a cantilever beam made of a magnetoactive elastomer. An experiment was designed to characterize dynamic responses of the MSR under different magnetic stimuli at relatively higher frequencies to evaluate the rate-dependent hysteresis effect. A hardware-in-the-loop technique in conjunction with a PID controller was implemented, which permitted the generation of a precise and uniform magnetic field. The MSR was subjected to uniform magnetic loading perpendicular to the robot’s length leading to large amplitudes and rates of harmonic movements of the MSR. The experiments were performed under different intensities, ranging from 2 to 30 mT, at frequencies up to 3 Hz. The measured data were analyzed to obtain response time-histories and frequency response characteristics of the MSR, apart from the motion snapshots.
{"title":"An experimental investigation of dynamic motions of a small-scale magnetoactive soft robot undergoing large nonlinear movements","authors":"S. Moezi, R. Sedaghati, S. Rakheja","doi":"10.1117/12.2658376","DOIUrl":"https://doi.org/10.1117/12.2658376","url":null,"abstract":"Small-scale magnetoactive soft robots (MSRs) with multimodal locomotion and wireless actuation capabilities have emerged in recent years for various highly sensitive and precise biomedical tasks such as targeted drug delivery and minimally invasive therapies. MSRs comprise magnetoactive elastomers consisting of micron-sized hard magnetic particles, such as neodymium-iron-boron (NdFeB), suspended or arranged into an elastomeric matrix. These robots generally exhibit large deformation under an applied magnetics stimulus, which is considered favorable for the aforementioned applications. Only limited efforts, however, have been reported on characterization of such robots. This is likely due to their nonlinear dynamics, especially under large deformations and hysteretic stress-strain characteristics, which strongly depend on the magnitude and frequency of the external magnetic stimuli. This study experimentally investigated and analyzed the real-time nonlinear and hysteretic responses of a MSR fabricated in the form of a cantilever beam made of a magnetoactive elastomer. An experiment was designed to characterize dynamic responses of the MSR under different magnetic stimuli at relatively higher frequencies to evaluate the rate-dependent hysteresis effect. A hardware-in-the-loop technique in conjunction with a PID controller was implemented, which permitted the generation of a precise and uniform magnetic field. The MSR was subjected to uniform magnetic loading perpendicular to the robot’s length leading to large amplitudes and rates of harmonic movements of the MSR. The experiments were performed under different intensities, ranging from 2 to 30 mT, at frequencies up to 3 Hz. The measured data were analyzed to obtain response time-histories and frequency response characteristics of the MSR, apart from the motion snapshots.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"54 1","pages":"124830N - 124830N-10"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75890067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soft polymer actuators are in increasing demand due to their more fluid like motion and flexibility when actuated than compared with rigid actuators, which makes them valuable in diverse engineering applications. One of the main types of soft polymer actuators is the dielectric elastomer actuator, whose working principle is to apply a voltage potential difference between electrodes to reduce the thickness of the elastomeric material while expanding its area. This paper looks at manufacturing a micro soft polymer dielectric elastomer actuator utilizing two-photon polymerization 3D printing. The actuator contains micro channels that are filled with an electrode by using capillary action. A complex helical geometry is designed, printed, and tested for electrode filling capabilities. Quite a few obstacles are described in this paper including the use of a newly released two-photon polymerization resin which has limited supporting resources, as well as the complex helical geometry having a large compliance that vastly complicates its fabrication, post-processing, handling, electrode filling, electrode integration, and actuation testing. However, these challenges are overcome by using the standard printing recipes currently available for the resins, adding electrode isolation layers, and printing thicker elastomer zones for more structural support. The results found solidify the approach of filling microchannels with electrodes through capillary action and lead to further the focus and creation of multi-functional micro soft actuators.
{"title":"Electrode filling using capillary action of 3D printed elastomer microchannels","authors":"Taylor Stark, Daewon Kim","doi":"10.1117/12.2658146","DOIUrl":"https://doi.org/10.1117/12.2658146","url":null,"abstract":"Soft polymer actuators are in increasing demand due to their more fluid like motion and flexibility when actuated than compared with rigid actuators, which makes them valuable in diverse engineering applications. One of the main types of soft polymer actuators is the dielectric elastomer actuator, whose working principle is to apply a voltage potential difference between electrodes to reduce the thickness of the elastomeric material while expanding its area. This paper looks at manufacturing a micro soft polymer dielectric elastomer actuator utilizing two-photon polymerization 3D printing. The actuator contains micro channels that are filled with an electrode by using capillary action. A complex helical geometry is designed, printed, and tested for electrode filling capabilities. Quite a few obstacles are described in this paper including the use of a newly released two-photon polymerization resin which has limited supporting resources, as well as the complex helical geometry having a large compliance that vastly complicates its fabrication, post-processing, handling, electrode filling, electrode integration, and actuation testing. However, these challenges are overcome by using the standard printing recipes currently available for the resins, adding electrode isolation layers, and printing thicker elastomer zones for more structural support. The results found solidify the approach of filling microchannels with electrodes through capillary action and lead to further the focus and creation of multi-functional micro soft actuators.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"33 1","pages":"124820D - 124820D-7"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77545193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Capacitive dielectric elastomer sensors (DES) are well-known in robotic sensing applications due to their sensitivity and stability under tensile strain. These sensors rely on changes in geometry to detect deformation. Since DES are thin, they are resistant to out-of-plane compression and this is made more difficult if they are bonded to a rigid surface. Here, we present a new type of DES that detects changes in the fringe field between interdigitated electrodes (IDEs). This is made possible using a compression sensitive silicone/carbon black composite that sits atop the electrodes. The IDEs create a fringing field extending into the composite whose relative permittivity can change by 250% when compressed. As a result, there is no longer any design challenges brought on by the incompressibility of elastomers. Additionally, since compliant electrodes are not required in this configuration, and the electrodes are kept in a single plane on a commercial PCB, the fabrication process is simple. This sensor is convenient to be used as a tactile sensor for either conventional rigid or soft robotic grippers, allowing the safe manipulation of soft and delicate objects.
{"title":"For dielectric elastomers, fringe-sensing is not as quirky as it sounds","authors":"M. H. Mahmoudinezhad, Iain A. Anderson, S. Rosset","doi":"10.1117/12.2658676","DOIUrl":"https://doi.org/10.1117/12.2658676","url":null,"abstract":"Capacitive dielectric elastomer sensors (DES) are well-known in robotic sensing applications due to their sensitivity and stability under tensile strain. These sensors rely on changes in geometry to detect deformation. Since DES are thin, they are resistant to out-of-plane compression and this is made more difficult if they are bonded to a rigid surface. Here, we present a new type of DES that detects changes in the fringe field between interdigitated electrodes (IDEs). This is made possible using a compression sensitive silicone/carbon black composite that sits atop the electrodes. The IDEs create a fringing field extending into the composite whose relative permittivity can change by 250% when compressed. As a result, there is no longer any design challenges brought on by the incompressibility of elastomers. Additionally, since compliant electrodes are not required in this configuration, and the electrodes are kept in a single plane on a commercial PCB, the fabrication process is simple. This sensor is convenient to be used as a tactile sensor for either conventional rigid or soft robotic grippers, allowing the safe manipulation of soft and delicate objects.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"18 1","pages":"124820A - 124820A-9"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80034573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sydney A. Giannuzzi, A. M. Rodríguez, Seth P. Pietrowski, Jeffrey L. Kauffman
This paper presents a fundamental non-contact valve design developed by integrating a ring-stack piezoelectric actuator into a converging nozzle design to impart harmonic flow. The paper also outlines the governing equations as well as limiting factors that constrain the design and operating performance. The converging nozzle design achieves choked flow at the valve exit when the nozzle is fully open. Valve actuation centers around piezoelectric ring stacks: the piezoelectric stack is fixed within the valve on one end to the base plate and has a conical nozzle tip attached to the opposite end of the stack. When the stack fully displaces to its maximum length, the nozzle tip is in the closed position where minimal flow passes through the valve exit. The flow area between the nozzle tip and casing wall achieves maximum mass flow rate when the piezoelectric stack is at minimum length. The change in flow cross-sectional area due to the piezoelectric stack displacement generates a change in mass flow rate through the valve. Due to the small-scale displacement of piezoelectric stacks, different angles of the nozzle cone and casing are required to achieve a greater desired mass flow rate. This model is adjustable to accommodate various piezoelectric stack sizes and displacements or to alter the exit mass flow rate to best suit a particular application.
{"title":"Piezoelectric ring-stack actuator design for high-frequency valve","authors":"Sydney A. Giannuzzi, A. M. Rodríguez, Seth P. Pietrowski, Jeffrey L. Kauffman","doi":"10.1117/12.2658565","DOIUrl":"https://doi.org/10.1117/12.2658565","url":null,"abstract":"This paper presents a fundamental non-contact valve design developed by integrating a ring-stack piezoelectric actuator into a converging nozzle design to impart harmonic flow. The paper also outlines the governing equations as well as limiting factors that constrain the design and operating performance. The converging nozzle design achieves choked flow at the valve exit when the nozzle is fully open. Valve actuation centers around piezoelectric ring stacks: the piezoelectric stack is fixed within the valve on one end to the base plate and has a conical nozzle tip attached to the opposite end of the stack. When the stack fully displaces to its maximum length, the nozzle tip is in the closed position where minimal flow passes through the valve exit. The flow area between the nozzle tip and casing wall achieves maximum mass flow rate when the piezoelectric stack is at minimum length. The change in flow cross-sectional area due to the piezoelectric stack displacement generates a change in mass flow rate through the valve. Due to the small-scale displacement of piezoelectric stacks, different angles of the nozzle cone and casing are required to achieve a greater desired mass flow rate. This model is adjustable to accommodate various piezoelectric stack sizes and displacements or to alter the exit mass flow rate to best suit a particular application.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"15 1","pages":"124830I - 124830I-10"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85189671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energy from mechanical vibrations is prevalent in the ambient, which can be effectively harvested using triboelectric generators. However, the efficiency of the harvesters is limited by the narrow bandwidth. Herein, we propose combining Vibro-impact and magnetic nonlinearity for Polydimethylsiloxane-based triboelectric energy harvesters to extend the operation bandwidth and enhance the efficiency of the traditional triboelectric harvesters. Our harvester design consists of a cantilever beam with a tip magnet facing another fixed magnet at the same polarity, inducing a nonlinear magnetic repulsive force. The lower surface of the tip magnet acts as an upper electrode of a triboelectric harvester, while the lower electrode with attached Polydimethylsiloxane (PDMS) insulator. Under the effect of base excitation, the system can vibrate in monostable or bistable oscillations by varying the distance between the two magnets, causing an impact on the triboelectric electrodes, and an alternative electrical signal is generated at a wide range of frequencies. The harvester’s static and dynamic behaviors are investigated theoretically and experimentally validated at different separation distances between the two magnets. We achieved higher bandwidth by combining Vibro-impact with magnetic nonlinearity, and triboelectric energy harvesters show promising applications for future wireless sensor networks at wider operation frequency bandwidth.
{"title":"A vibro-impact triboelectric energy harvester with magnetic bistability for wide bandwidth","authors":"Qais Qaseem, Alwathiqbellah Ibrahim","doi":"10.1117/12.2657602","DOIUrl":"https://doi.org/10.1117/12.2657602","url":null,"abstract":"Energy from mechanical vibrations is prevalent in the ambient, which can be effectively harvested using triboelectric generators. However, the efficiency of the harvesters is limited by the narrow bandwidth. Herein, we propose combining Vibro-impact and magnetic nonlinearity for Polydimethylsiloxane-based triboelectric energy harvesters to extend the operation bandwidth and enhance the efficiency of the traditional triboelectric harvesters. Our harvester design consists of a cantilever beam with a tip magnet facing another fixed magnet at the same polarity, inducing a nonlinear magnetic repulsive force. The lower surface of the tip magnet acts as an upper electrode of a triboelectric harvester, while the lower electrode with attached Polydimethylsiloxane (PDMS) insulator. Under the effect of base excitation, the system can vibrate in monostable or bistable oscillations by varying the distance between the two magnets, causing an impact on the triboelectric electrodes, and an alternative electrical signal is generated at a wide range of frequencies. The harvester’s static and dynamic behaviors are investigated theoretically and experimentally validated at different separation distances between the two magnets. We achieved higher bandwidth by combining Vibro-impact with magnetic nonlinearity, and triboelectric energy harvesters show promising applications for future wireless sensor networks at wider operation frequency bandwidth.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"15 1","pages":"124830W - 124830W-14"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80348619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ceaseless quest to realize novel classes of functional materials has provided new road maps to material autonomy. Autonomous materials and structures offer advanced functionalities such as sensing, actuation, selfhealing, communication, and computing to create a sense–decide–respond loop. They have numerous applications in robotics, human-machine interfacing, micro/nano-electromechanical systems, and flexible electronics. During the past decades, tremendous effort has been made to push the development of autonomous materials and structures. This paper presents an overview of the recent progresses, challenges and futures trends in autonomous materials and structures. In the area of material autonomy, active multifunctional metamaterials appear to open enormous field of study. Their scalability is an important feature to create building blocks for multiscale autonomous structures. Thus, this review paper provides an insight into their developments and future trends. The foreseeable challenges are further discussed.
{"title":"Advances in autonomous materials and structures","authors":"Qianyun Zhang, Amir H. Alavi","doi":"10.1117/12.2658156","DOIUrl":"https://doi.org/10.1117/12.2658156","url":null,"abstract":"The ceaseless quest to realize novel classes of functional materials has provided new road maps to material autonomy. Autonomous materials and structures offer advanced functionalities such as sensing, actuation, selfhealing, communication, and computing to create a sense–decide–respond loop. They have numerous applications in robotics, human-machine interfacing, micro/nano-electromechanical systems, and flexible electronics. During the past decades, tremendous effort has been made to push the development of autonomous materials and structures. This paper presents an overview of the recent progresses, challenges and futures trends in autonomous materials and structures. In the area of material autonomy, active multifunctional metamaterials appear to open enormous field of study. Their scalability is an important feature to create building blocks for multiscale autonomous structures. Thus, this review paper provides an insight into their developments and future trends. The foreseeable challenges are further discussed.","PeriodicalId":89272,"journal":{"name":"Smart structures and materials. Nondestructive evaluation for health monitoring and diagnostics","volume":"33 1","pages":"124830U - 124830U-10"},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82374446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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