Pub Date : 2024-09-02DOI: 10.1088/1361-665x/ad717a
Sina Kazemipour, Osgar John Ohanian III, Maurizio Porfiri, Peng Zhang
Webbing structures are critical load-bearing components in a wide array of applications from structural restraint layers in inflatable space habitats to safety harness belts used by construction workers. In the field, webbings are subjected to ultraviolet (UV) irradiation from sunlight, leading to material degradation and a loss of mechanical strength. To date, health monitoring of webbings has relied on empirically correlating UV-induced strength loss with variations in their inherent color, which often yields inconsistent and imprecise results. To fill this gap, we propose a novel class of photochromic webbing structures that afford noninvasive monitoring of UV-induced degradation of their mechanical strength. The webbings’ sensing capabilities are achieved by integrating a class of photochromic yarns, fabricated through a pressurized coating process. Under continuous UV irradiation, the proposed photochromic webbings exhibit a substantial color change, demonstrating a sensing lifetime equivalent to several months in field conditions. We establish a strong correlation between the webbings’ photochromic response and their strength loss, supporting the feasibility of the proposed webbings in monitoring their mechanical integrity. To elucidate the sensing mechanism, we propose a physics-based mathematical model that describes the underlying photochemical reactions. Through an asymptotic analysis, we demonstrate that the model accurately predicts the webbing’s long-term photochromic responses under extended UV irradiation. The proposed photochromic webbing structures and the predictive mathematical model could enhance the safety and integrity of webbing-based engineering systems.
{"title":"Photochromic webbing structures for monitoring UV-induced mechanical strength degradation","authors":"Sina Kazemipour, Osgar John Ohanian III, Maurizio Porfiri, Peng Zhang","doi":"10.1088/1361-665x/ad717a","DOIUrl":"https://doi.org/10.1088/1361-665x/ad717a","url":null,"abstract":"Webbing structures are critical load-bearing components in a wide array of applications from structural restraint layers in inflatable space habitats to safety harness belts used by construction workers. In the field, webbings are subjected to ultraviolet (UV) irradiation from sunlight, leading to material degradation and a loss of mechanical strength. To date, health monitoring of webbings has relied on empirically correlating UV-induced strength loss with variations in their inherent color, which often yields inconsistent and imprecise results. To fill this gap, we propose a novel class of photochromic webbing structures that afford noninvasive monitoring of UV-induced degradation of their mechanical strength. The webbings’ sensing capabilities are achieved by integrating a class of photochromic yarns, fabricated through a pressurized coating process. Under continuous UV irradiation, the proposed photochromic webbings exhibit a substantial color change, demonstrating a sensing lifetime equivalent to several months in field conditions. We establish a strong correlation between the webbings’ photochromic response and their strength loss, supporting the feasibility of the proposed webbings in monitoring their mechanical integrity. To elucidate the sensing mechanism, we propose a physics-based mathematical model that describes the underlying photochemical reactions. Through an asymptotic analysis, we demonstrate that the model accurately predicts the webbing’s long-term photochromic responses under extended UV irradiation. The proposed photochromic webbing structures and the predictive mathematical model could enhance the safety and integrity of webbing-based engineering systems.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of textile-based strain sensors signifies a new era for diverse e-textile applications spanning various fields, including health monitoring and sensing equipment. Over decades, the sensor field has experienced significant advancements, incorporating enhancements in sensing accuracy, resolution, measurement range, and robustness, among other aspects. Our article initially focuses on the creation of textile-based strain membrane sensors customized for a range of industrial applications, such as air filter clogging detection and airflow analysis. In the subsequent part of the study, the reliability and washability performance of the sensing membrane, without mechanical damage, were investigated. To achieve this, thermoplastic polyurethane nanofibers were utilized to fabricate a textile sensory membrane. Subsequently, this membrane air transparent (low-pressure drop) and highly resilient was used as a substrate to print strain gauge tracks using carbon conductive ink, with the aid of a flexible printed circuit board printer. The resulting samples underwent comprehensive evaluation for reliability and washability. Prototype membranes were subjected to twelve wash cycles in a top-loading washing machine to assess washing reliability. Both the mechanical and electromechanical properties of the strain membrane sensors were examined both before and after the washing process. The gauge factor of the straight line decreased from 18.14 (region I) and 86.03 (region II) to 20.22 after washing. This value reduced from 0.88 and 4.20 to 0.33, and from 13 and 2.77 to 3.29 and 0.81 for the big zigzag and small zigzag, respectively. Similarly, electrical resistance change after 12 wash cycles was negligible with maximum change 1.12. These results indicate that sensors maintain their functionality even after exposure to multiple washing cycles. In conclusion, it can be inferred that textile-based sensory membranes are well-suited for industrial applications aiming at the measurement of low and high-speed airflows subject to rigorous washing and other potential mechanical stresses.
{"title":"Preparation and reliability performance evaluation of electro-spun strain sensing membrane","authors":"Parian Mohamadi, Shahood uz Zaman, Elham Mohsenzadeh, Cedric Cochrane, Vladan Koncar","doi":"10.1088/1361-665x/ad70e2","DOIUrl":"https://doi.org/10.1088/1361-665x/ad70e2","url":null,"abstract":"The development of textile-based strain sensors signifies a new era for diverse e-textile applications spanning various fields, including health monitoring and sensing equipment. Over decades, the sensor field has experienced significant advancements, incorporating enhancements in sensing accuracy, resolution, measurement range, and robustness, among other aspects. Our article initially focuses on the creation of textile-based strain membrane sensors customized for a range of industrial applications, such as air filter clogging detection and airflow analysis. In the subsequent part of the study, the reliability and washability performance of the sensing membrane, without mechanical damage, were investigated. To achieve this, thermoplastic polyurethane nanofibers were utilized to fabricate a textile sensory membrane. Subsequently, this membrane air transparent (low-pressure drop) and highly resilient was used as a substrate to print strain gauge tracks using carbon conductive ink, with the aid of a flexible printed circuit board printer. The resulting samples underwent comprehensive evaluation for reliability and washability. Prototype membranes were subjected to twelve wash cycles in a top-loading washing machine to assess washing reliability. Both the mechanical and electromechanical properties of the strain membrane sensors were examined both before and after the washing process. The gauge factor of the straight line decreased from 18.14 (region I) and 86.03 (region II) to 20.22 after washing. This value reduced from 0.88 and 4.20 to 0.33, and from 13 and 2.77 to 3.29 and 0.81 for the big zigzag and small zigzag, respectively. Similarly, electrical resistance change after 12 wash cycles was negligible with maximum change 1.12. These results indicate that sensors maintain their functionality even after exposure to multiple washing cycles. In conclusion, it can be inferred that textile-based sensory membranes are well-suited for industrial applications aiming at the measurement of low and high-speed airflows subject to rigorous washing and other potential mechanical stresses.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrospinning is a versatile technique widely used to produce polymer fibres with diameters ranging from several micrometres to tens of nanometres. This unique technique enables the production of thin fibres and charges the fibres in parallel. However, precise comparisons between electrospinning and other charging techniques have been limited. In this study, the charging properties of electrospun microfibre mats fabricated using atactic poly(styrene) (aPS) were compared with those of corona-charged microfibre mats fabricated using the same material (aPS) and possessing the same structure. The results showed that the surface potentials of electrospun aPS fibre mats were approximately three times higher than those of corona-charged fibre mats, demonstrating that a significantly large amount of charge could be stored in electrospun fibre mats. A large amount of stored charge was maintained even after 240 d of storage in low-humidity, atmospheric, and high-humidity environments. Furthermore, mathematical models explaining the effective surface charge densities of electrospun and corona-charged fibre mats were proposed using the recently proposed model of stored charge distribution in fibre mats. Therefore, the clarified unique charging properties of electrospun aPS microfibre mats originally charged via electrospinning pave the way for the development of appropriate applications of electrospun charged polymer microfibres, submicrofibres, and nanofibres.
{"title":"Charging properties of atactic poly(styrene) microfibre mats charged with electrospinning and corona charging","authors":"Mitsuo Kaneko, Kenichi Takagaki, Rintaro Tsuchimoto, Yuya Ishii","doi":"10.1088/1361-665x/ad6bd8","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6bd8","url":null,"abstract":"Electrospinning is a versatile technique widely used to produce polymer fibres with diameters ranging from several micrometres to tens of nanometres. This unique technique enables the production of thin fibres and charges the fibres in parallel. However, precise comparisons between electrospinning and other charging techniques have been limited. In this study, the charging properties of electrospun microfibre mats fabricated using atactic poly(styrene) (aPS) were compared with those of corona-charged microfibre mats fabricated using the same material (aPS) and possessing the same structure. The results showed that the surface potentials of electrospun aPS fibre mats were approximately three times higher than those of corona-charged fibre mats, demonstrating that a significantly large amount of charge could be stored in electrospun fibre mats. A large amount of stored charge was maintained even after 240 d of storage in low-humidity, atmospheric, and high-humidity environments. Furthermore, mathematical models explaining the effective surface charge densities of electrospun and corona-charged fibre mats were proposed using the recently proposed model of stored charge distribution in fibre mats. Therefore, the clarified unique charging properties of electrospun aPS microfibre mats originally charged via electrospinning pave the way for the development of appropriate applications of electrospun charged polymer microfibres, submicrofibres, and nanofibres.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taking into account that shape memory polymer (SMP)-based devices are often subject to multiple environmental conditions during application, it is difficult to accurately predict their shape memory effect (SME). Thus, constitutive modeling for SMPs in multi-field environments is of great importance. However, most of the models available are limited to describing the temperature-driven SME and do not refer to multi-field conditions. In this paper, a constitutive model for SMPs in hygrothermal environments is developed under a consistent thermodynamic framework. The derivation is based on an additive decomposition of the Helmholtz free energy density and satisfying the first law and second law of thermodynamics. In this paper, the absorbed moisture is categorized into free and bound phases and it is considered that they have different effects on the material properties. Accordingly, it is the first time to study the variation of configurational entropy with different phases in the polymer–moisture system during the moisture diffusion process. For the first time, the validity of the constitutive model proposed in this paper can be confirmed by systematically comparing the modeling results and experimental data of various types of hygrothermal-induced shape memory cycles.
考虑到基于形状记忆聚合物（SMP）的设备在应用过程中通常会受到多种环境条件的影响，因此很难准确预测其形状记忆效应（SME）。因此，建立多场环境下的 SMP 构成模型非常重要。然而，现有的大多数模型仅限于描述温度驱动的 SME，并未涉及多场条件。本文在一个一致的热力学框架下，为湿热环境中的 SME 建立了一个构造模型。该模型的推导基于亥姆霍兹自由能密度的加法分解，并满足热力学第一定律和第二定律。本文将吸收的水分分为自由相和结合相，并认为它们对材料特性有不同的影响。因此，本文首次研究了聚合物-水分体系在水分扩散过程中构型熵随不同相的变化。通过系统比较各种类型湿热诱导形状记忆循环的建模结果和实验数据，首次证实了本文提出的构成模型的有效性。
{"title":"Thermodynamically-consistent constitutive modeling of moisture- and thermo-responsive shape memory polymers","authors":"Jianping Gu, Changchun Wang, Xiaopeng Zhang, Hao Zeng, Mengqi Wan, Huiyu Sun","doi":"10.1088/1361-665x/ad70e3","DOIUrl":"https://doi.org/10.1088/1361-665x/ad70e3","url":null,"abstract":"Taking into account that shape memory polymer (SMP)-based devices are often subject to multiple environmental conditions during application, it is difficult to accurately predict their shape memory effect (SME). Thus, constitutive modeling for SMPs in multi-field environments is of great importance. However, most of the models available are limited to describing the temperature-driven SME and do not refer to multi-field conditions. In this paper, a constitutive model for SMPs in hygrothermal environments is developed under a consistent thermodynamic framework. The derivation is based on an additive decomposition of the Helmholtz free energy density and satisfying the first law and second law of thermodynamics. In this paper, the absorbed moisture is categorized into free and bound phases and it is considered that they have different effects on the material properties. Accordingly, it is the first time to study the variation of configurational entropy with different phases in the polymer–moisture system during the moisture diffusion process. For the first time, the validity of the constitutive model proposed in this paper can be confirmed by systematically comparing the modeling results and experimental data of various types of hygrothermal-induced shape memory cycles.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-665x/ad6ecd
Huan Zhang, Lei Deng, Jin Zhao, Weihua Li, Haiping Du
Electric vehicle (EV) drivetrains have witnessed remarkable progress, prompting intensified research into advanced transmission systems. Magnetorheological fluids (MRF) clutches offer precise modulation of input currents, enabling swift and seamless torque delivery for EV transmission systems, owing to their exceptional performance. The transmission of an EV requires MRF-based clutches to deliver a precise and rapid torque transfer during gear shifting. In these scenarios, the inherent current rate-dependent hysteresis of the MRF-based clutches between the output torque and input current poses a significant challenge in accurately regulating output torque. Therefore, an accurate clutch model of the MRF-based clutches that can describe the rate-dependent hysteresis is crucial to achieve precise control of the output torque. This study investigates the nonlinear hysteresis phenomena using a prototyped MRF dual-clutch (MRFDC) for the transmission system of EVs, followed by a comprehensive analysis of three widely used hysteresis models: two parametric models, including the Bouc-Wen (BW) model and algebraic model (AM), and a non-parametric model, the NARX model. Accuracy, fitting time, and stack size are selected as the main indicators to evaluate the three models comprehensively. Results indicate that the NARX model has exceptional accuracy compared to the others, while it has a much higher memory requirement. The algebraic model shows a great advantage in computational efficiency because it has a straightforward expression. The BW model is in the middle position for all three indicators. To optimize the classic BW model (CBW), a fractional-order modified BW model (FOMBW) is proposed based on the polynomial input function and fractional-order derivatives. The proposed FOMBW model demonstrates superior capability in capturing asymmetric and rate-dependent characteristics compared to the CBW model. These findings provide the basis for choosing an appropriate model to effectively capture nonlinear current hysteresis phenomena within MRFDC with the requirement for precise torque control during gear shifting.
{"title":"Comparative analysis and optimization of nonlinear hysteresis models for a magnetorheological fluid dual-clutch of an electric vehicle transmission","authors":"Huan Zhang, Lei Deng, Jin Zhao, Weihua Li, Haiping Du","doi":"10.1088/1361-665x/ad6ecd","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6ecd","url":null,"abstract":"Electric vehicle (EV) drivetrains have witnessed remarkable progress, prompting intensified research into advanced transmission systems. Magnetorheological fluids (MRF) clutches offer precise modulation of input currents, enabling swift and seamless torque delivery for EV transmission systems, owing to their exceptional performance. The transmission of an EV requires MRF-based clutches to deliver a precise and rapid torque transfer during gear shifting. In these scenarios, the inherent current rate-dependent hysteresis of the MRF-based clutches between the output torque and input current poses a significant challenge in accurately regulating output torque. Therefore, an accurate clutch model of the MRF-based clutches that can describe the rate-dependent hysteresis is crucial to achieve precise control of the output torque. This study investigates the nonlinear hysteresis phenomena using a prototyped MRF dual-clutch (MRFDC) for the transmission system of EVs, followed by a comprehensive analysis of three widely used hysteresis models: two parametric models, including the Bouc-Wen (BW) model and algebraic model (AM), and a non-parametric model, the NARX model. Accuracy, fitting time, and stack size are selected as the main indicators to evaluate the three models comprehensively. Results indicate that the NARX model has exceptional accuracy compared to the others, while it has a much higher memory requirement. The algebraic model shows a great advantage in computational efficiency because it has a straightforward expression. The BW model is in the middle position for all three indicators. To optimize the classic BW model (CBW), a fractional-order modified BW model (FOMBW) is proposed based on the polynomial input function and fractional-order derivatives. The proposed FOMBW model demonstrates superior capability in capturing asymmetric and rate-dependent characteristics compared to the CBW model. These findings provide the basis for choosing an appropriate model to effectively capture nonlinear current hysteresis phenomena within MRFDC with the requirement for precise torque control during gear shifting.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-665x/ad70e5
C Medina, H Canché, A I Oliva-Avilés, F Avilés
The mechanical, electrical, and piezoresistive responses of multilayer graphene sheet (GS)/polypropylene (PP) nanocomposites are investigated using four GSs of distinctive physicochemical properties. It is found that the morphology of the interconnected network of GS agglomerates at the mesoscale governs the mechanical, electrical, and electro-mechanical (piezoresistive) properties of the PP nanocomposites. The morphology of the mesoscale network of electroconductive fillers governs the effective properties of the nanocomposite. This network morphology strongly depends on the GS lateral size, dispersion, agglomeration, and, to a lesser extent, the specific surface area of the GSs. Within the range of lateral sizes investigated herein (1–21 μm), larger GSs yields nanocomposites with higher electrical conductivity. On the other hand, GSs of moderate lateral size (∼6.5 μm) and specific surface area of ∼141 m2 g−1 render GS/PP nanocomposites with a more dispersed and more sparsely interconnected network. This better dispersed network with agglomerates of smaller dimensions is concomitant with improved stiffness and strength, and higher gauge factors (∼18.2) for this GS/PP nanocomposites. Excellent capabilities for detection of human motion were proved for these nanocomposites.
{"title":"Electromechanical response of multilayer graphene sheet/polypropylene nanocomposites and its relationship with the graphene sheet physicochemical properties","authors":"C Medina, H Canché, A I Oliva-Avilés, F Avilés","doi":"10.1088/1361-665x/ad70e5","DOIUrl":"https://doi.org/10.1088/1361-665x/ad70e5","url":null,"abstract":"The mechanical, electrical, and piezoresistive responses of multilayer graphene sheet (GS)/polypropylene (PP) nanocomposites are investigated using four GSs of distinctive physicochemical properties. It is found that the morphology of the interconnected network of GS agglomerates at the mesoscale governs the mechanical, electrical, and electro-mechanical (piezoresistive) properties of the PP nanocomposites. The morphology of the mesoscale network of electroconductive fillers governs the effective properties of the nanocomposite. This network morphology strongly depends on the GS lateral size, dispersion, agglomeration, and, to a lesser extent, the specific surface area of the GSs. Within the range of lateral sizes investigated herein (1–21 <italic toggle=\"yes\">μ</italic>m), larger GSs yields nanocomposites with higher electrical conductivity. On the other hand, GSs of moderate lateral size (∼6.5 <italic toggle=\"yes\">μ</italic>m) and specific surface area of ∼141 m<sup>2</sup> g<sup>−1</sup> render GS/PP nanocomposites with a more dispersed and more sparsely interconnected network. This better dispersed network with agglomerates of smaller dimensions is concomitant with improved stiffness and strength, and higher gauge factors (∼18.2) for this GS/PP nanocomposites. Excellent capabilities for detection of human motion were proved for these nanocomposites.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-665x/ad7002
Yinlong Zhu, Tian Wang, Weizhuang Gong, Kai Feng, Xu Wang, Shuang Xi
Soft robotic arms have been widely explored in recent years because of their excellent flexibility and infinite degrees of freedom which distinguishes them form traditional rigid robots. This paper focuses on the design, fabrication and kinematic analysis of a new modular soft robotic arm featuring multiple segments, each one with three degrees of freedom. In contrast to most research, this paper utilizes soft pneu-net structure instead of fiber-reinforced structure, thereby preventing large local strains due to membrane pressurized against a fiber reinforcement. We employed finite element method and orthogonal experiment were to ascertain the optimal structural parameters. Furthermore, we present the kinematic model of the soft arm by the parameterization of the Denavit–Hartenberg convention under the basis of constant curvature assumption. Finally, the experimental evaluation of the soft robotic arm including bending angle, elongation, deflection and flexibility test were carried out. The experimental data, particularly concerning the bending angle and spatial position of both single modular and two-modular soft arm agree well with the finite element method simulation. Additionally, we performed both grasping and obstacle-avoidance grasping tests for dual modular soft robotic. The results demonstrate that the soft robotic arm exhibits superior performance and highlights its potential for various applications.
{"title":"Design and motion analysis of soft robotic arm with pneumatic-network structure","authors":"Yinlong Zhu, Tian Wang, Weizhuang Gong, Kai Feng, Xu Wang, Shuang Xi","doi":"10.1088/1361-665x/ad7002","DOIUrl":"https://doi.org/10.1088/1361-665x/ad7002","url":null,"abstract":"Soft robotic arms have been widely explored in recent years because of their excellent flexibility and infinite degrees of freedom which distinguishes them form traditional rigid robots. This paper focuses on the design, fabrication and kinematic analysis of a new modular soft robotic arm featuring multiple segments, each one with three degrees of freedom. In contrast to most research, this paper utilizes soft pneu-net structure instead of fiber-reinforced structure, thereby preventing large local strains due to membrane pressurized against a fiber reinforcement. We employed finite element method and orthogonal experiment were to ascertain the optimal structural parameters. Furthermore, we present the kinematic model of the soft arm by the parameterization of the Denavit–Hartenberg convention under the basis of constant curvature assumption. Finally, the experimental evaluation of the soft robotic arm including bending angle, elongation, deflection and flexibility test were carried out. The experimental data, particularly concerning the bending angle and spatial position of both single modular and two-modular soft arm agree well with the finite element method simulation. Additionally, we performed both grasping and obstacle-avoidance grasping tests for dual modular soft robotic. The results demonstrate that the soft robotic arm exhibits superior performance and highlights its potential for various applications.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-665x/ad7003
Choonghan Lee, Woosoon Yim
Magnetorheological elastomers (MREs) are materials that leverage magnetic forces among ferromagnetic particles to induce variable stiffness and damping under external magnetic fields. However, conventional MREs have limitations in achieving reduced stiffness when exposed to an external magnetic field. In response to the need for rapid and bidirectional changes in stiffness, this research proposes a novel approach—pre-magnetized MREs—using permanently magnetized ferromagnetic particles instead of an external permanent magnet for magnetic bias. The pre-magnetized MRE, fabricated with silica-coated neodymium alloy particles and silicone elastomer, undergoes a comprehensive investigation of design parameters, including silicone resin selection, particle thickness, size, and weight ratio. The study explores the directional effects of pre-magnetization through simulations, considering forces among magnetized particles and the hyperelasticity of the elastomer. Experimental investigations involve measuring shear moduli for different shear strains under varying magnetization directions. The results highlight the impact of resin type, particle size, and weight ratio on the magnetorheological (MR) effect. Additionally, an application testbed is developed to assess bi-directional changes in stiffness for various core materials. The study reveals a correlation between MR effect/response time and the magnetic permeabilities of core materials, along with the attraction and repulsion forces between the core and magnetized particles. Observations indicate that the MR effect for different core materials ranges from 0.08% to 0.25%, with response times measured at 40 and 46 ms for forward and reverse currents, respectively. The findings contribute valuable insights into optimizing the design and performance of pre-magnetized MREs for enhanced bi-directional stiffness control in engineering applications.
{"title":"Development of pre-magnetized magnetorheological elastomer for bidirectionally variable stiffness applications","authors":"Choonghan Lee, Woosoon Yim","doi":"10.1088/1361-665x/ad7003","DOIUrl":"https://doi.org/10.1088/1361-665x/ad7003","url":null,"abstract":"Magnetorheological elastomers (MREs) are materials that leverage magnetic forces among ferromagnetic particles to induce variable stiffness and damping under external magnetic fields. However, conventional MREs have limitations in achieving reduced stiffness when exposed to an external magnetic field. In response to the need for rapid and bidirectional changes in stiffness, this research proposes a novel approach—pre-magnetized MREs—using permanently magnetized ferromagnetic particles instead of an external permanent magnet for magnetic bias. The pre-magnetized MRE, fabricated with silica-coated neodymium alloy particles and silicone elastomer, undergoes a comprehensive investigation of design parameters, including silicone resin selection, particle thickness, size, and weight ratio. The study explores the directional effects of pre-magnetization through simulations, considering forces among magnetized particles and the hyperelasticity of the elastomer. Experimental investigations involve measuring shear moduli for different shear strains under varying magnetization directions. The results highlight the impact of resin type, particle size, and weight ratio on the magnetorheological (MR) effect. Additionally, an application testbed is developed to assess bi-directional changes in stiffness for various core materials. The study reveals a correlation between MR effect/response time and the magnetic permeabilities of core materials, along with the attraction and repulsion forces between the core and magnetized particles. Observations indicate that the MR effect for different core materials ranges from 0.08% to 0.25%, with response times measured at 40 and 46 ms for forward and reverse currents, respectively. The findings contribute valuable insights into optimizing the design and performance of pre-magnetized MREs for enhanced bi-directional stiffness control in engineering applications.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1088/1361-665x/ad7215
Hongchen Miao, Xi Cao, Mingtao Fu
This work introduces a double-layer metasurface to isolate the fundamental shear horizontal wave (SH0 wave). The metasurface is designed to split the SH0 wave source into two parts and then manipulate the two waves to be out of phase and have equal amplitude upon reaching the end of the metasurface. This results in interference cancellation, effectively blocking the propagation of SH0 waves into the protected zone. Firstly, the metasurface is designed theoretically, utilizing rectangular strips to constitute the substructure. Subsequently, finite element simulations are conducted to verify the correctness of the theoretical design. Finally, the metasurface is fabricated using 3D printing, and its performance is evaluated through experiments. The results indicate that the metasurface can function as a cage for SH0 waves, trapping different types of SH0 waves located at any position within the cage. Furthermore, when the source of SH0 waves is positioned outside the cage, the metasurface can effectively impede their propagation into the interior region of the cage. The proposed double-layer metasurface provides a simple approach to blocking SH0 waves, which may have potential applications in practical engineering.
{"title":"Double-layer metasurface for blocking the fundamental SH wave","authors":"Hongchen Miao, Xi Cao, Mingtao Fu","doi":"10.1088/1361-665x/ad7215","DOIUrl":"https://doi.org/10.1088/1361-665x/ad7215","url":null,"abstract":"This work introduces a double-layer metasurface to isolate the fundamental shear horizontal wave (SH<sub>0</sub> wave). The metasurface is designed to split the SH<sub>0</sub> wave source into two parts and then manipulate the two waves to be out of phase and have equal amplitude upon reaching the end of the metasurface. This results in interference cancellation, effectively blocking the propagation of SH<sub>0</sub> waves into the protected zone. Firstly, the metasurface is designed theoretically, utilizing rectangular strips to constitute the substructure. Subsequently, finite element simulations are conducted to verify the correctness of the theoretical design. Finally, the metasurface is fabricated using 3D printing, and its performance is evaluated through experiments. The results indicate that the metasurface can function as a cage for SH<sub>0</sub> waves, trapping different types of SH<sub>0</sub> waves located at any position within the cage. Furthermore, when the source of SH<sub>0</sub> waves is positioned outside the cage, the metasurface can effectively impede their propagation into the interior region of the cage. The proposed double-layer metasurface provides a simple approach to blocking SH<sub>0</sub> waves, which may have potential applications in practical engineering.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1088/1361-665x/ad6ed0
Jiaxi Jin, Xuan Sun, Yuechen Liu, Zhaobo Chen
The paper introduces a novel active-passive integrated vibration isolator based on metal rubber and piezoelectric actuator, along with an adaptive active vibration control strategy. The active control strategy employs the adaptive dynamic step filtered-x normalized least mean squares algorithm, allowing the step size to adaptively adjust with the error. The secondary control path of the algorithm is modeled using the enhanced rate-dependent Prandtl–Ishlinskii model and the auto-regressive with extra inputs model. The active-passive integrated vibration isolator achieves broadband vibration isolation from 10 to 200 Hz. Compared to passive isolation, the transmissibility decreases from 0.99 to 0.056 at 10 Hz, from 3.02 to 0.068 at the resonance frequency, and from 0.057 to 0.046 at 200 Hz. This study provides a theoretical and experimental foundation for the design of a novel, broadband, and efficient active-passive integrated vibration isolator structure and active control method.
{"title":"Research on active-passive integrated vibration isolator based on metal rubber and piezoelectric actuator","authors":"Jiaxi Jin, Xuan Sun, Yuechen Liu, Zhaobo Chen","doi":"10.1088/1361-665x/ad6ed0","DOIUrl":"https://doi.org/10.1088/1361-665x/ad6ed0","url":null,"abstract":"The paper introduces a novel active-passive integrated vibration isolator based on metal rubber and piezoelectric actuator, along with an adaptive active vibration control strategy. The active control strategy employs the adaptive dynamic step filtered-x normalized least mean squares algorithm, allowing the step size to adaptively adjust with the error. The secondary control path of the algorithm is modeled using the enhanced rate-dependent Prandtl–Ishlinskii model and the auto-regressive with extra inputs model. The active-passive integrated vibration isolator achieves broadband vibration isolation from 10 to 200 Hz. Compared to passive isolation, the transmissibility decreases from 0.99 to 0.056 at 10 Hz, from 3.02 to 0.068 at the resonance frequency, and from 0.057 to 0.046 at 200 Hz. This study provides a theoretical and experimental foundation for the design of a novel, broadband, and efficient active-passive integrated vibration isolator structure and active control method.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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