Smart Materials and Structures最新文献

{"title":"Reversible negative compressibility metamaterials inspired by Braess’s Paradox","authors":"Jinmeng Zha and Zhen Zhang","doi":"10.1088/1361-665x/ad59e6","DOIUrl":"https://doi.org/10.1088/1361-665x/ad59e6","url":null,"abstract":"Negative compressibility metamaterials have attracted significant attention due to their distinctive properties and promising applications. Negative compressibility has been interpreted in two ways. Regarding the negative compressibility induced by a uniaxial load, it can only occur abruptly when the load reaches a certain threshold. Hence, it can be termed as transient negative compressibility. However, fabrication and experiments of such metamaterials have rarely been reported. Herein, we demonstrate them. Inspired by Braess’s paradox, a novel mechanical model is proposed with reversible negative compressibility. It shows multiple types of force responses during a loading-unloading cycle, including transient negative compressibility and hysteresis. Phase diagrams are employed to visualize the relationship between force responses and system parameters. Besides, explicit expressions for the conditions and intensity of negative compressibility are obtained for design and optimization. The model replacement method inspired by compliant mechanism design is then introduced to derive specific unit cell structures, thus avoiding intuition-based approaches. Additive manufacturing technology is utilized to fabricate the prototypes, and negative compressibility is validated via simulations and experiments. Furthermore, it is demonstrated that metamaterials with transient negative compressibility can be activated through electrical heating and can function as actuators, thereby possessing machine-like properties. The proposed mechanical metamaterial and the introduced design methodology have potentials to impact micro-electromechanical systems, force sensors, protective devices, and other applications.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"117 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513528","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}

{"title":"Implementation of tunable frequency-dependent stiffness elements via integrated shunted piezoelectric stacks","authors":"B Van Damme, R Weber, J U Schmied, A Spierings and A Bergamini","doi":"10.1088/1361-665x/ad588e","DOIUrl":"https://doi.org/10.1088/1361-665x/ad588e","url":null,"abstract":"Piezoelectric transducers applied on or integrated in structures, combined with appropriate circuits have been extensively investigated as a smart approach to the mitigation of resonant vibrations with high relative amplitudes. A resonant shunt circuit consisting of the capacitive piezoelectric transducer and an inductance can be configured to target specific eigenmodes of a structure, if appropriately placed and tuned. Their effect is expressed in terms of mechanical impedance of the host structure, allowing for the exchange of energy between the mechanical and electrical domain, to dramatically affect the dynamic response of the structure. By re-framing the function of resonant shunted piezoelectric transducers as frequency dependent variable stiffness elements, this paper investigates their capability to realize a frequency dependent structural mechanical connectivity, where the load path within a lattice structure can be interrupted at will for specific frequencies by tunable null-stiffness components. Here, we offer the numerical and experimental verification of this idea, by demonstrating the ability to significantly affect the dynamic response of a unit cell of an adaptive lattice metamaterial, even away from a structural resonance. In the latter case, the null-stiffness shunt leads to an additional resonance peak in the truss’ dynamic response. Its realization as additively manufactured component points to the feasibility of such structures in real life.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"26 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513527","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}

{"title":"Kresling origami derived structures and inspired mechanical metamaterial","authors":"Xiaolei Wang, Haibo Qu, Kai Zhao, Xiao Yang and Sheng Guo","doi":"10.1088/1361-665x/ad5a5a","DOIUrl":"https://doi.org/10.1088/1361-665x/ad5a5a","url":null,"abstract":"Origami has attracted more and more attention due to its exotic mechanical properties, and the inspired metamaterials are also popular. However, the main focus of current research is on existing origami patterns and properties, although new origami patterns or results that expand on existing origami patterns are gradually emerging. In this paper, we summarize a series of derived structures of the Kresling origami, demonstrating more stable states and richer structural forms. At the same time, a point-searching method is proposed along the ideas of the truss model, which is effective for irregular stable states of these derived structures. On this basis, we create an origami-inspired mechanical metamaterial with foldable property and high load-bearing capacity, fabricate the prototype, and validate its performance through experiments. These works make important contributions for promoting the Kresling origami and origami-inspired metamaterials.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"27 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530529","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}

{"title":"Deformation mechanism of the dual thermo-sensitive hydrogel bilayer structure","authors":"Huilong Jiang, Jincheng Lei and Zishun Liu","doi":"10.1088/1361-665x/ad5944","DOIUrl":"https://doi.org/10.1088/1361-665x/ad5944","url":null,"abstract":"Thermo-sensitive hydrogel is a smart soft material that undergoes significant volume deformation in response to temperature changes, making it highly applicable in soft smart actuators. However, traditional thermo-sensitive hydrogel bilayer structures are often characterized by slow response rates and limited unidirectional bending capabilities. To overcome these limitations, a new thermo-sensitive hydrogel bilayer structure with faster response and bidirectional deformation is proposed in this work. This structure consists of two active thermo-sensitive hydrogel layers with different thermo-sensitive effect, in which one shrinks and the other swells when the temperature changes. The hydrogels with the fastest temperature response are identified by optimizing the monomer fraction and used to create the bilayer structure. The deformation states of the dual thermo-sensitive hydrogel bilayer structure are controlled by regulating the phase state of the both layers, resulting in different deformation patterns under varied temperature in experiments. We have established a model to describe the deformation of the bilayer structure. Finally, the capability of the bilayer structure to mimic human body movements and the blooming and wilting of flowers is demonstrated. This work reveals the deformation mechanism for a novel dual thermo-sensitive hydrogel bilayer structure, which holds great significance for the advancement of soft smart actuators.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"27 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513530","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}

{"title":"Pattern reconfigurable antenna with specified main lobe deflection and stable bandwidth by using bistable composite laminates","authors":"Mingyue Zhang, Wei Tong, Guangyu Xu, Qi Wang and Renjing Gao","doi":"10.1088/1361-665x/ad5943","DOIUrl":"https://doi.org/10.1088/1361-665x/ad5943","url":null,"abstract":"Pattern reconfiguration of antennas has become a very important measure to improve the signal gain and working bandwidth by manipulating beam direction. Developing rational methods to find the reconfigurable structure is a key problem. In this paper, a collaborative optimization method is proposed to comprehensively consider both the geometric parameters of the bistable substrate and the size of the radiation patch. This method enables the design of a pattern reconfigurable antenna with specified main lobe deflection and stable bandwidth. Specifically, by using a two-step process, the log-periodic dipole antenna (LPDA) is conformally mapped from the planar substrate to the bistable substrate. Further investigation reveals that the main lobe deflection angle and bandwidth stability are influenced by the geometric parameters of the bistable substrate and the size of radiation dipoles, respectively. Thus, these parameters are selected as design variables for solving the proposed collaborative optimization model. The transformation between two stable configurations enables the proposed LPDA to deflect the main lobe of the H-plane pattern by 30° while maintaining consistency in the E-plane patterns. Importantly, the resonant frequencies remain unaffected and the bandwidth does not decrease during the pattern reconfiguration. Notably, the pattern reconfigurable mechanism is rooted in that the transformation between the two stable configurations alters the number and position of the dipoles in the radiation region and their current path, thereby changing the radiation direction of electromagnetic waves. The proposed collaborative optimization method has a potential application for other types of antennas and offers opportunities for various applications in the field of wireless communication.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"85 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513529","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}

{"title":"Developing self-calibrating system for fiber Bragg grating based guided wave sensing under changing temperature conditions","authors":"Rohan Soman and Pawel Kudela","doi":"10.1088/1361-665x/ad56e6","DOIUrl":"https://doi.org/10.1088/1361-665x/ad56e6","url":null,"abstract":"Fiber Bragg grating (FBG) sensors have long been thought of as the ideal sensors for structural health monitoring (SHM) due to their small size, light weight, ability to be embedded and ability to be multiplexed. So, FBG sensors have been commonly used for strain based SHM. In recent times, a renewed interest is seen in the use of FBG sensors for guided wave (GW) measurements using the edge filtering approach which increases the sensitivity several folds. They offer several unique opportunities for GW based SHM such as allowing mode filtering, acoustic coupling, etc. Unfortunately, more wide spread research is limited by the steep learning curve. Also, the use of FBG in real applications is still in its infancy due to the need of calibration of the system when the ambient temperature conditions change. This paper precisely tries to address these two shortcomings. For overcoming the steep learning curve, a detailed discussion on the hardware for the FBG based GW sensing is provided. Following the discussion a step-by-step approach is outlined for incorporating the sensors. A detailed trouble-shooting guide is developed based on the immense experience of the authors in this field. This exercise will allow easier adoption of the technique and stimulate more research in the topic. The exercise also allows us to highlight the safeguards and the features that need to be included in the system which will be self-calibrating. Once the design parameters are established a self-calibrating autonomous FBG based sensing system is developed. The developed system is tested in ambient conditions over an extended period in the day capturing the ambient temperature changes. The system is also tested in a larger temperature range (25 ∘C–65 ∘C). The results indicate that indeed the self-calibrating system works effectively. Some sensitivity studies to determine the performance in terms of system reaction time have also been provided. Such a ‘smart’ autonomous system for GW sensing has not been presented to the best of the author’s knowledge and is the key novelty of the presented work. Furthermore, the detailed discussions and troubleshooting guide will help introduce more people to this field of study which will lead to more radical development of the field.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"79 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504773","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}

{"title":"Insight into constitutive theories of 4D printed polymer materials: a review","authors":"Jesus A Rodriguez-Morales, Hao Duan, Jianping Gu, Hao Zeng and Huiyu Sun","doi":"10.1088/1361-665x/ad523c","DOIUrl":"https://doi.org/10.1088/1361-665x/ad523c","url":null,"abstract":"Four-dimensional (4D) printing has emerged as a branch of additive manufacturing that utilizes stimuli-responsive materials to generate three-dimensional structures with functional features. In this context, constitutive models play a paramount role in designing engineering structures and devices using 4D printing, as they help understand mechanical behavior and material responses to external stimuli, providing a theoretical framework for predicting and analyzing their deformation and shape-shifting capabilities. This article thoroughly discusses available constitutive models for single-printed and multi-printed materials. Later, we explore the role of machine learning (ML) algorithms in inferring constitutive relations, particularly in viscoelastic problems and, more recently, in shape memory polymers. Moreover, challenges and opportunities presented by both approaches for predicting the mechanical behavior of 4D printed polymer materials are examined. Finally, we concluded our discussion with a summary and some future perspectives expected in this field. This review aims to open a dialogue among the mechanics community to assess the limitations of analytical models and encourage the responsible use of emerging techniques, such as ML. By clarifying these aspects, we intend to advance the understanding and application of constitutive models in the rapidly growing field of 4D printing.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"1 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513531","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}

{"title":"Functional capsule robots: a review of locomotion, pose, medical operation and wireless power transmission reported in 2018–2023","authors":"Dezheng Hua, Lei Deng, Janusz Gołdasz, Xinhua Liu, Haiping Du, Grzegorz Królczyk, Weihua Li and Zhixiong Li","doi":"10.1088/1361-665x/ad52d8","DOIUrl":"https://doi.org/10.1088/1361-665x/ad52d8","url":null,"abstract":"As a new type of medical equipment, capsule robots are actuated wirelessly by space magnetic field, which have important application advantages in the diagnosis and treatment of gastrointestinal diseases. Active locomotion is the basis of medical operation for capsule robots, as well as an important guarantee to avoid misdetection and retention in the body. Furthermore, the pose estimation of the capsule robots in the gastrointestinal tract can provide accurate information for medical operation and improve work efficiency. Specific medical operation is one of the ultimate goals of capsule robots, and it is the key to realize the non-invasive diagnosis and treatment technology. Moreover, replacing traditional chemical batteries with wireless power transfer technology not only reduces the dimensions of the capsule robots, but also provides unlimited possibilities for the development of medical operations. In this work, the state-of-the-art capsule robots are reviewed according to the research directions of the locomotion, pose, medical operation and wireless power transmission reported from 2018 to 2023. In light of the four main directions of the capsule robots, some important research achievements and approaches are summarized. In particular, some outstanding advances on innovative structure, efficient methodology and appropriate application of the capsule robots are introduced in details. Finally, an overview of the significant issues occurred in the capsule robots is reported, and the developing trends are discussed.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"26 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513489","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}

{"title":"Electrical/thermal triggering on shape memory composite tubes with different braiding angles","authors":"Qin Yang, Renyi Liu, Bohong Gu, Baozhong Sun, Chaofeng Han and Wei Zhang","doi":"10.1088/1361-665x/ad525a","DOIUrl":"https://doi.org/10.1088/1361-665x/ad525a","url":null,"abstract":"2D braided shape memory composite (SMPC) tubes, with near-net shape manufacturing and programmable, are widely utilized in smart structures. Here we have developed braided tubes of continuous carbon fiber reinforced shape memory polyurethane (SMPU) composites. This innovative design yields a synergistic boost in both mechanical strength, shape memory functionality, and dual-trigger responsiveness. The mechanical properties, electrical/thermal shape memory performance, and recovery force of the SMPC tubes with various braiding angles have been investigated. The effects of braiding angle, temperature dependence, and applied current on the mechanical properties and shape memory properties were revealed. We found a substantial increase in compression load and ring stiffness as the braiding angle increased and the temperature decreased. The SMPC tubes exhibited a recovery ratio of 99% under electrical and thermal triggering, demonstrating a more rapid shape recovery compared to the SMPU tubes solely under thermal triggering. The large-angle specimens exhibited shorter recovery times, higher recovery forces (up to 11.40 N), and faster responses upon electrical stimulation. The ability of SMPC tubes to generate a recovery force several times greater than their weight holds great potential for expanding the applications of smart actuators.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"2010 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513488","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}

{"title":"Development of an inertia-driven resonant piezoelectric stack pump based on the flexible support structure","authors":"Jian Chen, Rong Jin, Wenzhi Gao, Changhai Liu, Yishan Zeng and Jingwu Wang","doi":"10.1088/1361-665x/ad523d","DOIUrl":"https://doi.org/10.1088/1361-665x/ad523d","url":null,"abstract":"This paper proposes an inertia-driven resonant piezoelectric stack pump based on a flexible support structure to solve the problem that the piezoelectric stack cannot effectively drive the diaphragm pump to transport liquid due to too small output displacement and too high resonant frequency when one end is fixed. Under the inertial force generated by the vibration of the piezoelectric stack’s mass center during its deformation, the whole piezoelectric stack will vibrate with the flexible support structure; and a large displacement and inertial force can be achieved to drive the pump at the resonant frequency. Piezoelectric pumps are designed with a diaphragm pump and a piezoelectric stack based on the flexible support structure. The piezoelectric vibrator includes a piezoelectric stack, a preloading component and a flexible support plate. A fixed support plate and three flexible support plates with different stiffnesses were fabricated and assembled with the same piezoelectric stack and diaphragm pump respectively to construct four piezoelectric pump prototypes with different resonant frequencies. The temperature rise characteristics of the piezoelectric stack were experimentally studied to determine the safe range of the driving voltage and frequency. Then the output performances of the piezoelectric pumps were tested. Under a sinusoidal driving voltage of 100 Vpp, the piezoelectric pump based on the fixed support structure cannot pump water, while the piezoelectric pumps based on the flexible support structure achieved the maximum flow rates of 89.0 ml min−1, 123.4 ml min−1 and 197.4 ml min−1 at the resonant frequencies of 262 Hz, 297 Hz and 354 Hz, and the maximum backpressures of 4.4 kPa, 7.5 kPa and 11.0 kPa at 266 Hz, 309 Hz and 365 Hz.","PeriodicalId":21656,"journal":{"name":"Smart Materials and Structures","volume":"29 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504774","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}