Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies最新文献
Squid are the fastest aquatic invertebrates through jetting locomotion. This done through a mantle that quickly compresses an internal fluid, forcing fluid out through a funnel. The squid mantle has a complex collagen fiber and muscular system and squid propulsion is primarily done through circumferential muscles (90°) contracting around the mantel, forcing fluid out of the mantel. However, jetting is also increased through elastic energy stored in the helically-wound IM-1 collagen fibers, which have been measured between 28° to 32° in different species of squid. Inspired by the muscular and collagen fiber configuration found in the squid mantel, new composite pumps with active fibers oriented at precise angles around a cylindrical tube are proposed. An analytical model of the active fiber composite pump is developed. Results show that maximum pumping power and efficiency is achieved with a wind angle of 90° and a matrix modulus that is equal to the fiber modulus.
{"title":"Bio-Inspired Active Fiber Composite Pumps","authors":"M. Philen","doi":"10.1115/SMASIS2018-8077","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8077","url":null,"abstract":"Squid are the fastest aquatic invertebrates through jetting locomotion. This done through a mantle that quickly compresses an internal fluid, forcing fluid out through a funnel. The squid mantle has a complex collagen fiber and muscular system and squid propulsion is primarily done through circumferential muscles (90°) contracting around the mantel, forcing fluid out of the mantel. However, jetting is also increased through elastic energy stored in the helically-wound IM-1 collagen fibers, which have been measured between 28° to 32° in different species of squid. Inspired by the muscular and collagen fiber configuration found in the squid mantel, new composite pumps with active fibers oriented at precise angles around a cylindrical tube are proposed. An analytical model of the active fiber composite pump is developed. Results show that maximum pumping power and efficiency is achieved with a wind angle of 90° and a matrix modulus that is equal to the fiber modulus.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125909585","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}
Portable, wearable, and mobile devices are becoming more and more popular in the past two decades. Those devices rely on batteries heavily as power source. However, the limited life span of batteries constitutes a limitation. Human body energy harvesting has the potential to power those devices, thus replacing batteries or extending battery life. Harvesting positive muscle work from human body can be a burden, and exhausts the wearer. In this paper, we developed a biomechanical energy-harvesting device that generates electricity by harvesting negative work during human walking. The energy harvester mounts on the ankle and selectively engages to generate power between the middle stance phase and terminal stance phase, during which the calf muscles do negative work. The device harvests negative energy by assisting muscles in performing negative work. Test subjects walking with the device produced an average of 0.94 watts of electric power. From treadmill test, the device was shown to harvest energy only during the negative work phase, as a result it has the potential to not to increase the metabolic cost. Producing substantial electricity without burden on the wearer makes this harvester well suited for powering wearable, portable, and mobile devices.
{"title":"Energy Harvesting From Ankle: Generating Electricity by Harvesting Negative Work","authors":"Mingyi Liu, Wei-Che Tai, L. Zuo","doi":"10.1115/SMASIS2018-8041","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8041","url":null,"abstract":"Portable, wearable, and mobile devices are becoming more and more popular in the past two decades. Those devices rely on batteries heavily as power source. However, the limited life span of batteries constitutes a limitation. Human body energy harvesting has the potential to power those devices, thus replacing batteries or extending battery life. Harvesting positive muscle work from human body can be a burden, and exhausts the wearer. In this paper, we developed a biomechanical energy-harvesting device that generates electricity by harvesting negative work during human walking. The energy harvester mounts on the ankle and selectively engages to generate power between the middle stance phase and terminal stance phase, during which the calf muscles do negative work. The device harvests negative energy by assisting muscles in performing negative work. Test subjects walking with the device produced an average of 0.94 watts of electric power. From treadmill test, the device was shown to harvest energy only during the negative work phase, as a result it has the potential to not to increase the metabolic cost. Producing substantial electricity without burden on the wearer makes this harvester well suited for powering wearable, portable, and mobile devices.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120988206","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}
Linsen Xu, Jinfu Liu, Jiajun Xu, Xuan Wu, Shengyao Fan
In this article, a novel wall-climbing locomotion mechanism, which can adapt multiple wall surfaces is developed to imitate the special animals, such as geckoes or flies. The spiny and adhesive belts are adopted in this robot to implement climbing on different kinds of wall surfaces instead of the vacuum generator for moving quietly and quickly. The switching mechanism is brought out to realize the belts switching between different surfaces, and a tail made up of two torsional springs and a supporting part is designed to overcome the robot’s overturning moment. So the mechanical system of the robot consists of four parts: the power and drive system, the moving mechanisms (spiny and adhesive), the switching system and the tail. Then the virtual prototyping of the robot with multi-locomotion modes is brought out, and the different gaits on the rough surface, the smooth surface and the transition process are analyzed. During the spine gait using the spine belts, the adhesive force should overcome the robot gravity and drive it, so the drive torque can obtained by building the force balance equations of the robot, which include the supporting forces of the spine belts and the tail. During the adhesive gait using the adhesive rubber belts, the force balance equations should include the supporting forces of the adhesive belts and the tail. And during the transition gait, the force balance equations include all of the above forces. So the mechanical model of the robot can be built according to the above analysis. Finally, the experimental prototype of the wall-climbing robot is manufactured and the wall-climbing experiments are carried out to testify its functions. The experiments show that the robot can adapt to different wall surfaces, and the torque parameters obtained based on the dynamics model can ensure the robot to locomote stably.
{"title":"Design and Experimental Study of a Bioinspired Wall-Climbing Robot With Multi-Locomotion Modes","authors":"Linsen Xu, Jinfu Liu, Jiajun Xu, Xuan Wu, Shengyao Fan","doi":"10.1115/SMASIS2018-7925","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7925","url":null,"abstract":"In this article, a novel wall-climbing locomotion mechanism, which can adapt multiple wall surfaces is developed to imitate the special animals, such as geckoes or flies. The spiny and adhesive belts are adopted in this robot to implement climbing on different kinds of wall surfaces instead of the vacuum generator for moving quietly and quickly. The switching mechanism is brought out to realize the belts switching between different surfaces, and a tail made up of two torsional springs and a supporting part is designed to overcome the robot’s overturning moment. So the mechanical system of the robot consists of four parts: the power and drive system, the moving mechanisms (spiny and adhesive), the switching system and the tail. Then the virtual prototyping of the robot with multi-locomotion modes is brought out, and the different gaits on the rough surface, the smooth surface and the transition process are analyzed. During the spine gait using the spine belts, the adhesive force should overcome the robot gravity and drive it, so the drive torque can obtained by building the force balance equations of the robot, which include the supporting forces of the spine belts and the tail. During the adhesive gait using the adhesive rubber belts, the force balance equations should include the supporting forces of the adhesive belts and the tail. And during the transition gait, the force balance equations include all of the above forces. So the mechanical model of the robot can be built according to the above analysis. Finally, the experimental prototype of the wall-climbing robot is manufactured and the wall-climbing experiments are carried out to testify its functions. The experiments show that the robot can adapt to different wall surfaces, and the torque parameters obtained based on the dynamics model can ensure the robot to locomote stably.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129941834","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}
Passive infrared (PIR) sensors are the most popular deployed sensors in building lighting control for individual presence detection. However, PIR sensors are motion detectors in nature, responding only to incident radiation variation, which lead to false negative detections, inaccurate occupancy estimation, and uncomfortable lighting swings, short lifetime of the equipment, and waste of energy. In this study, a shutter driven by a Lavet motor PIR (LAMPIR) sensor is developed for presence detection for both stationary and moving occupants. Building off our previous work on chopped PIR (C-PIR) and rotationally-chopped PIR (Ro-PIR) sensors, Lavet motor, a single-phase electro-mechanical vibrator, is introduced, which has many advantages over traditional servo motors and stepper motors in terms of power consumption, size, weight and noise level. Driven by pulsed signal from a microcontroller unit (MCU), the electro-mechanical vibrator drives a semi-transparent long-wave infrared (LWIR) optical shutter to shutter the field of view (FOV) of a PIR sensor periodically. Output voltage generated by a LAMPIR senor for occupied and unoccupied scenarios can be monitored and analyzed to identify presence accurately. Parametric studies are conducted to find the optimal setting of driving signal frequency, shutter width and shuttering period. The LAMPIR sensor reaches an accuracy of 100% for detecting stationary occupants up to a range of 4.5 m and moving occupants up to a range of 10 m, which improves the detection range of both C-PIR and Ro-PIR sensors (4.0 m for stationary and 8.0 m for moving occupancy detection). LAMPIR has a FOV of 90° in horizontal and 100° in vertical, which is reasonable for most applications. For a 17-hour-long presence detection test, LAMPIR can reach an accuracy of 93.52% to classify unoccupied, stationary and moving occupant scenarios. More importantly, the average power consumption of LAMPIR is 0.19 W, which is 82% less than that of the C-PIR sensor and 89% less than that of the Ro-PIR sensor.
{"title":"Shuttered Passive Infrared Sensor for Occupancy Detection: Exploring a Low Power Electro-Mechanical Driving Approach","authors":"Libo Wu, Ya Wang","doi":"10.1115/SMASIS2018-8112","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8112","url":null,"abstract":"Passive infrared (PIR) sensors are the most popular deployed sensors in building lighting control for individual presence detection. However, PIR sensors are motion detectors in nature, responding only to incident radiation variation, which lead to false negative detections, inaccurate occupancy estimation, and uncomfortable lighting swings, short lifetime of the equipment, and waste of energy. In this study, a shutter driven by a Lavet motor PIR (LAMPIR) sensor is developed for presence detection for both stationary and moving occupants. Building off our previous work on chopped PIR (C-PIR) and rotationally-chopped PIR (Ro-PIR) sensors, Lavet motor, a single-phase electro-mechanical vibrator, is introduced, which has many advantages over traditional servo motors and stepper motors in terms of power consumption, size, weight and noise level. Driven by pulsed signal from a microcontroller unit (MCU), the electro-mechanical vibrator drives a semi-transparent long-wave infrared (LWIR) optical shutter to shutter the field of view (FOV) of a PIR sensor periodically. Output voltage generated by a LAMPIR senor for occupied and unoccupied scenarios can be monitored and analyzed to identify presence accurately. Parametric studies are conducted to find the optimal setting of driving signal frequency, shutter width and shuttering period. The LAMPIR sensor reaches an accuracy of 100% for detecting stationary occupants up to a range of 4.5 m and moving occupants up to a range of 10 m, which improves the detection range of both C-PIR and Ro-PIR sensors (4.0 m for stationary and 8.0 m for moving occupancy detection). LAMPIR has a FOV of 90° in horizontal and 100° in vertical, which is reasonable for most applications. For a 17-hour-long presence detection test, LAMPIR can reach an accuracy of 93.52% to classify unoccupied, stationary and moving occupant scenarios. More importantly, the average power consumption of LAMPIR is 0.19 W, which is 82% less than that of the C-PIR sensor and 89% less than that of the Ro-PIR sensor.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130684001","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}
Haofeng Chen, Yanan Zhang, Xuan Wu, XiaojieĀ Wang, Linsen Xu, Ningning Zhang, Zhaochun Li
This paper presents a method to measure gripping force of a bipedal wall-climbing robot (WCR) with spiny toe pads. The spiny toe pad is designed based on inspiration of an insect’s tarsal system. Each foot of the robot consists of a pair of opposed linear spiny arrays. The foot employs a pulley system to actuate the arrays via four pairs of tension and compression springs. Two Hall effect sensors are embedded into the robot feet to sense the gripping force by detecting the linear deformation of the springs. The two Hall effect sensors are calibrated and the relationship between the voltage signal output of the sensors and displacement is established before measuring gripping force. Then the consistency and accuracy of Hall effect sensor measurement method are verified by comparing with a commercial force sensor. A horizontal crawling test of the WCR is carried out and the gripping force verse time when the WCR moves. The experimental results show that the measured force history is in accordance with the actual movement states.
{"title":"Gripping Force Measurement of a Bioinspired Wall-Climbing Robot With Spiny Toe Pads","authors":"Haofeng Chen, Yanan Zhang, Xuan Wu, XiaojieĀ Wang, Linsen Xu, Ningning Zhang, Zhaochun Li","doi":"10.1115/SMASIS2018-8139","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8139","url":null,"abstract":"This paper presents a method to measure gripping force of a bipedal wall-climbing robot (WCR) with spiny toe pads. The spiny toe pad is designed based on inspiration of an insect’s tarsal system. Each foot of the robot consists of a pair of opposed linear spiny arrays. The foot employs a pulley system to actuate the arrays via four pairs of tension and compression springs. Two Hall effect sensors are embedded into the robot feet to sense the gripping force by detecting the linear deformation of the springs. The two Hall effect sensors are calibrated and the relationship between the voltage signal output of the sensors and displacement is established before measuring gripping force. Then the consistency and accuracy of Hall effect sensor measurement method are verified by comparing with a commercial force sensor. A horizontal crawling test of the WCR is carried out and the gripping force verse time when the WCR moves. The experimental results show that the measured force history is in accordance with the actual movement states.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132002367","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}
Total Knee Replacement (TKR) is an important and in-demand procedure for the aging population of the United States. In recent decades, the number of TKR procedures performed has shown an increase. This pattern is expected to continue in the coming decades. Despite medical advances in orthopedic surgery, a high number of patients, approximately 20%, are dissatisfied with their procedure outcomes. Common causes that are suggested for this dissatisfaction include loosening of the implant components as well as infection. To eliminate loosening as a cause, it is necessary to determine the state of the implant both intra- and post-operatively. Previous research has focused on passively sensing the compartmental loads between the femoral and tibial components. Common methods include using strain gauges or even piezoelectric transducers to measure force. An alternative to this is to perform real-time structural health monitoring (SHM) of the implant to determine changes in the state of the system. A commonly investigated method of SHM, referred to as the electromechanical impedance (EMI) method, involves using the coupled electromechanical properties of piezoelectric transducers to measure the host structure’s condition. The EMI method has already shown promise in aerospace and infrastructure applications, but has seen limited testing for use in the biomechanical field. This work is intended to validate the EMI method for use in detecting damage in cemented bone-implant interfaces, with TKR being used as a case study to specify certain experimental parameters. An experimental setup which represents the various material layers found in a bone-implant interface is created with various damage conditions to determine the ability for a piezoelectric sensor to detect and quantify the change in material state. The objective of this work is to provide validation as well as a foundation on which additional work in SHM of orthopedic implants and structures can be performed.
{"title":"Validation of Impedance-Based Structural Health Monitoring in a Simulated Biomedical Implant System","authors":"Robert I. Ponder, M. Safaei, S. Anton","doi":"10.1115/SMASIS2018-8012","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8012","url":null,"abstract":"Total Knee Replacement (TKR) is an important and in-demand procedure for the aging population of the United States. In recent decades, the number of TKR procedures performed has shown an increase. This pattern is expected to continue in the coming decades. Despite medical advances in orthopedic surgery, a high number of patients, approximately 20%, are dissatisfied with their procedure outcomes. Common causes that are suggested for this dissatisfaction include loosening of the implant components as well as infection. To eliminate loosening as a cause, it is necessary to determine the state of the implant both intra- and post-operatively. Previous research has focused on passively sensing the compartmental loads between the femoral and tibial components. Common methods include using strain gauges or even piezoelectric transducers to measure force. An alternative to this is to perform real-time structural health monitoring (SHM) of the implant to determine changes in the state of the system. A commonly investigated method of SHM, referred to as the electromechanical impedance (EMI) method, involves using the coupled electromechanical properties of piezoelectric transducers to measure the host structure’s condition. The EMI method has already shown promise in aerospace and infrastructure applications, but has seen limited testing for use in the biomechanical field. This work is intended to validate the EMI method for use in detecting damage in cemented bone-implant interfaces, with TKR being used as a case study to specify certain experimental parameters. An experimental setup which represents the various material layers found in a bone-implant interface is created with various damage conditions to determine the ability for a piezoelectric sensor to detect and quantify the change in material state. The objective of this work is to provide validation as well as a foundation on which additional work in SHM of orthopedic implants and structures can be performed.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116742292","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}
Marcos Oliveira, Chang Liu, Mengtao Zhao, Samuel M. Felton
This paper presents a motor driven wrist brace that can adjust its stiffness by changing its mesoscale geometry. The design involves a plate structure that folds from a flexible flat shape to a stiff corrugated shape by means of a motor driven tendon. The structure is built using a laminate of rigid and flexible layers, with embedded flexural hinges that allow it to fold. The paper proposes a simplified analytical model to predict stiffness, and physical three-point bending tests indicate that the brace can increase its stiffness up to fifty times by folding.
{"title":"Design of a Variable Stiffness Wrist Brace With an Origami Structural Element","authors":"Marcos Oliveira, Chang Liu, Mengtao Zhao, Samuel M. Felton","doi":"10.1115/SMASIS2018-8049","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8049","url":null,"abstract":"This paper presents a motor driven wrist brace that can adjust its stiffness by changing its mesoscale geometry. The design involves a plate structure that folds from a flexible flat shape to a stiff corrugated shape by means of a motor driven tendon. The structure is built using a laminate of rigid and flexible layers, with embedded flexural hinges that allow it to fold. The paper proposes a simplified analytical model to predict stiffness, and physical three-point bending tests indicate that the brace can increase its stiffness up to fifty times by folding.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114668863","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 proposes a novel idea of a combined piezoelectric energy harvesting and torsional vibration absorber for rotating system. In particular, among possible alternative solutions for durable power sources useable in mechanical components, vibration represents a suitable method for the amount of power required to feed a wireless sensor network. For this purpose energy harvesting from structural vibration has received much attention in the past few years. Suitable vibration can be found in numerous mechanical environments including automotive moving structures, household applications, but also buildings and bridges. Similarly, a dynamic vibration absorber (DVA) is one of the most used devices to mitigate the vibration structures. This device is used to transfer the primary structural vibration to the auxiliary system. Thus, vibration energy is effectively localized in the secondary less sensitive structure and it can be harvested. This paper describes the design process of an energy harvesting tuned vibration absorber for rotating system using piezoelectricity components. Instead of being dissipated as heat, the energy of vibration is converted into electricity. The device proposed is designed to mitigate torsional vibrations as a rotational vibration absorber and to harvest energy as a power source for immediate use. The initial rotational multi degree of freedom system is initially reduced in equivalent single degree of freedom (SDOF) systems. An optimization method is used for evaluating the optimal mechanical parameters of the initial absorber for the SDOF systems defined. The design is modified for the integration of the active patches without detuning the absorber. In order to estimate the real power generated, a complex storage circuit is implemented. A fixed voltage is obtained as output. Through the introduction of a big capacitor, the energy stored is measured at different frequencies. Finally, the simultaneously achievement of the vibration reduction function and the energy harvesting function is evaluated.
{"title":"Design Development of Rotational Energy Harvesting Vibration Absorber (R-EHTVA)","authors":"F. Infante, W. Kaal, S. Perfetto, S. Herold","doi":"10.1115/SMASIS2018-7902","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7902","url":null,"abstract":"This paper proposes a novel idea of a combined piezoelectric energy harvesting and torsional vibration absorber for rotating system. In particular, among possible alternative solutions for durable power sources useable in mechanical components, vibration represents a suitable method for the amount of power required to feed a wireless sensor network. For this purpose energy harvesting from structural vibration has received much attention in the past few years. Suitable vibration can be found in numerous mechanical environments including automotive moving structures, household applications, but also buildings and bridges. Similarly, a dynamic vibration absorber (DVA) is one of the most used devices to mitigate the vibration structures. This device is used to transfer the primary structural vibration to the auxiliary system. Thus, vibration energy is effectively localized in the secondary less sensitive structure and it can be harvested. This paper describes the design process of an energy harvesting tuned vibration absorber for rotating system using piezoelectricity components. Instead of being dissipated as heat, the energy of vibration is converted into electricity. The device proposed is designed to mitigate torsional vibrations as a rotational vibration absorber and to harvest energy as a power source for immediate use. The initial rotational multi degree of freedom system is initially reduced in equivalent single degree of freedom (SDOF) systems. An optimization method is used for evaluating the optimal mechanical parameters of the initial absorber for the SDOF systems defined. The design is modified for the integration of the active patches without detuning the absorber. In order to estimate the real power generated, a complex storage circuit is implemented. A fixed voltage is obtained as output. Through the introduction of a big capacitor, the energy stored is measured at different frequencies. Finally, the simultaneously achievement of the vibration reduction function and the energy harvesting function is evaluated.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132361989","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}
Dielectric electroactive actuators (DEAs) are polymer materials capable of reallocating their shapes mechanically due to an electric stimulus [1]. They can also be used as sensors by producing an electrical change from an induced mechanical deformation [2]. However, production of these materials using traditional manufacturing methods is a challenging process. The use of additive manufacturing promises to be an improved method to overcome those challenges. In addition, selection of dielectric materials that can function as DEAs and are capable of being produced through additive manufacturing is challenging. The actuation capabilities of the DEA depend heavily on the electrical and mechanical material properties of the dielectric material used to build it, and not all dielectric materials have the capacity to function as DEAs. The likelihood of a material functioning as a DEA is difficult to predict due to the large number of variables. Therefore, this paper introduces a simple method for comparing materials, particularly 3-D printed materials for their viability to be used as DEAs. The study proposes a method to compare 3-D printable materials by using coefficients calculated from the materials’ electromechanical properties. This value is then compared to an ideal DEA material. The higher the value, the better the 3-D printable material will be in comparison to a selected optimal DEA material. The coefficient is based on a linear elastic model that describes the strain of the material in relation to the electromechanical pressure applied as a result of supplied voltage. This study tested three materials using a quantitative method along with experimental verification. The study demonstrates the relationship between the predictive coefficients and the physical actuation responses with disc-type actuators providing a simple method for predicting actuation potential of 3-D printable DEA material candidates.
{"title":"Prediction of Dielectric Electroactive Polymer Material Functionality","authors":"B. Newell, J. García, Angello Vindrola","doi":"10.1115/SMASIS2018-8166","DOIUrl":"https://doi.org/10.1115/SMASIS2018-8166","url":null,"abstract":"Dielectric electroactive actuators (DEAs) are polymer materials capable of reallocating their shapes mechanically due to an electric stimulus [1]. They can also be used as sensors by producing an electrical change from an induced mechanical deformation [2]. However, production of these materials using traditional manufacturing methods is a challenging process. The use of additive manufacturing promises to be an improved method to overcome those challenges. In addition, selection of dielectric materials that can function as DEAs and are capable of being produced through additive manufacturing is challenging.\u0000 The actuation capabilities of the DEA depend heavily on the electrical and mechanical material properties of the dielectric material used to build it, and not all dielectric materials have the capacity to function as DEAs. The likelihood of a material functioning as a DEA is difficult to predict due to the large number of variables. Therefore, this paper introduces a simple method for comparing materials, particularly 3-D printed materials for their viability to be used as DEAs.\u0000 The study proposes a method to compare 3-D printable materials by using coefficients calculated from the materials’ electromechanical properties. This value is then compared to an ideal DEA material. The higher the value, the better the 3-D printable material will be in comparison to a selected optimal DEA material. The coefficient is based on a linear elastic model that describes the strain of the material in relation to the electromechanical pressure applied as a result of supplied voltage.\u0000 This study tested three materials using a quantitative method along with experimental verification. The study demonstrates the relationship between the predictive coefficients and the physical actuation responses with disc-type actuators providing a simple method for predicting actuation potential of 3-D printable DEA material candidates.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129385456","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}
An electroactive polymer is a material capable of changing its size and shape when an electric field is present. It is composed of a thin film of dielectric elastomer and two electrodes placed on the top and bottom of the dielectric material. Since the rediscovery of their capabilities, electroactive polymers have been proposed as novel materials for use in numerous fields such as in bioengineering, electronics, hydraulics, and aerospace. It has been demonstrated that the actuation potential of electroactive polymer dielastomers can be significantly enhanced by mechanically pre-straining the material prior to application of an electric field. Application of uniform pre-strain is critical for uniform actuation and is challenging to achieve. This research details methods for constructing an automated uniform stretcher that resulted in the production of a LabView controlled iris stretcher for flexible materials. The high torque stretcher was capable of pre-straining materials with a minimum diameter of 1 inch mm) to a maximum diameter of 16 inches. The stretcher calculates the percent strain and has adjustable speed control through a high torque micro-stepper motor and controller. The stretcher’s capabilities were demonstrated on materials within varying tensile strengths up to 725 psi.
{"title":"Mechanical Iris Stretcher for Electroactive Polymers","authors":"Jose A. Romo-Estrada, B. Newell, J. García","doi":"10.1115/SMASIS2018-7964","DOIUrl":"https://doi.org/10.1115/SMASIS2018-7964","url":null,"abstract":"An electroactive polymer is a material capable of changing its size and shape when an electric field is present. It is composed of a thin film of dielectric elastomer and two electrodes placed on the top and bottom of the dielectric material. Since the rediscovery of their capabilities, electroactive polymers have been proposed as novel materials for use in numerous fields such as in bioengineering, electronics, hydraulics, and aerospace. It has been demonstrated that the actuation potential of electroactive polymer dielastomers can be significantly enhanced by mechanically pre-straining the material prior to application of an electric field. Application of uniform pre-strain is critical for uniform actuation and is challenging to achieve. This research details methods for constructing an automated uniform stretcher that resulted in the production of a LabView controlled iris stretcher for flexible materials. The high torque stretcher was capable of pre-straining materials with a minimum diameter of 1 inch mm) to a maximum diameter of 16 inches. The stretcher calculates the percent strain and has adjustable speed control through a high torque micro-stepper motor and controller. The stretcher’s capabilities were demonstrated on materials within varying tensile strengths up to 725 psi.","PeriodicalId":117187,"journal":{"name":"Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133226326","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}
Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies
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