Pub Date : 2025-03-01Epub Date: 2025-01-01DOI: 10.1016/j.eml.2024.102288
Saisneha Koppaka, David Doan, Wei Cai, Wendy Gu, Sindy K Y Tang
Cutting soft materials on the microscale has emerging applications in single-cell studies, tissue microdissection for organoid culture, drug screens, and other analyses. However, the cutting process is complex and remains incompletely understood. Furthermore, precise control over blade geometries, such as the blade tip radius, has been difficult to achieve. In this work, we use the Nanoscribe 3D printer to precisely fabricate micro-blades (i.e., blades <1 mm in length) and blade grid geometries. This fabrication method enables a systematic study of the effect of blade geometry on the indentation cutting of paraffin wax, a common tissue-embedding material. First, we print straight micro-blades with tip radius ranging from ~100 nm to 10 μm. The micro-blades are mounted in a custom nanoindentation setup to measure the cutting energy during indentation cutting of paraffin. Cutting energy, measured as the difference in dissipated energy between the first and second loading cycles, decreases as blade tip radius decreases, until ~357 nm when the cutting energy plateaus despite further decrease in tip radius. Second, we expand our method to blades printed in unconventional configurations, including parallel blade structures and blades arranged in a square grid. Under the conditions tested, the cutting energy scales approximately linearly with the total length of the blades comprising the blade structure. The experimental platform described can be extended to investigate other blade geometries and guide the design of microscale cutting of soft materials.
{"title":"Characterization of 3D printed micro-blades for cutting tissue-embedding material.","authors":"Saisneha Koppaka, David Doan, Wei Cai, Wendy Gu, Sindy K Y Tang","doi":"10.1016/j.eml.2024.102288","DOIUrl":"10.1016/j.eml.2024.102288","url":null,"abstract":"<p><p>Cutting soft materials on the microscale has emerging applications in single-cell studies, tissue microdissection for organoid culture, drug screens, and other analyses. However, the cutting process is complex and remains incompletely understood. Furthermore, precise control over blade geometries, such as the blade tip radius, has been difficult to achieve. In this work, we use the Nanoscribe 3D printer to precisely fabricate micro-blades (i.e., blades <1 mm in length) and blade grid geometries. This fabrication method enables a systematic study of the effect of blade geometry on the indentation cutting of paraffin wax, a common tissue-embedding material. First, we print straight micro-blades with tip radius ranging from ~100 nm to 10 μm. The micro-blades are mounted in a custom nanoindentation setup to measure the cutting energy during indentation cutting of paraffin. Cutting energy, measured as the difference in dissipated energy between the first and second loading cycles, decreases as blade tip radius decreases, until ~357 nm when the cutting energy plateaus despite further decrease in tip radius. Second, we expand our method to blades printed in unconventional configurations, including parallel blade structures and blades arranged in a square grid. Under the conditions tested, the cutting energy scales approximately linearly with the total length of the blades comprising the blade structure. The experimental platform described can be extended to investigate other blade geometries and guide the design of microscale cutting of soft materials.</p>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"75 ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11759486/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.eml.2024.102270
Shaoqi Huang, Yifan Li, Shuwen Zhang, Hu Zhao, Siyang Song, Chongpu Zhai, Minglong Xu
Friction control has attracted significant attention due to its potential to improve device efficiency and reduce wear. However, achieving rapid, reversible, and robust friction regulation remains a persistent challenge. In this study, we propose a novel strategy for contact control using electret films, which can effectively modulate electroadhesion to enable large-scale friction control. We develop a general model describing the interfacial electro-mechanical coupling mechanism, which is validated through systematic experiments. Both experimental and theoretical results demonstrate that the relationship between the pull-off force and the applied interfacial voltage follows a parabolic curve, with its maxima mainly depending on the charge density, thickness, and dielectric constant of the electret film. With the electret film of about 50 μm in thickness and an applied voltage of approximately 300 V, both the static and dynamic friction coefficients can be increased to more than twice their initial values. This study provides valuable insights into the optimization of mechanical systems in terms of performance enhancement, lifespan extension, energy losses, and thermal management.
{"title":"Electroadhesion-driven friction enhancement using electret films","authors":"Shaoqi Huang, Yifan Li, Shuwen Zhang, Hu Zhao, Siyang Song, Chongpu Zhai, Minglong Xu","doi":"10.1016/j.eml.2024.102270","DOIUrl":"10.1016/j.eml.2024.102270","url":null,"abstract":"<div><div>Friction control has attracted significant attention due to its potential to improve device efficiency and reduce wear. However, achieving rapid, reversible, and robust friction regulation remains a persistent challenge. In this study, we propose a novel strategy for contact control using electret films, which can effectively modulate electroadhesion to enable large-scale friction control. We develop a general model describing the interfacial electro-mechanical coupling mechanism, which is validated through systematic experiments. Both experimental and theoretical results demonstrate that the relationship between the pull-off force and the applied interfacial voltage follows a parabolic curve, with its maxima mainly depending on the charge density, thickness, and dielectric constant of the electret film. With the electret film of about 50 μm in thickness and an applied voltage of approximately 300 V, both the static and dynamic friction coefficients can be increased to more than twice their initial values. This study provides valuable insights into the optimization of mechanical systems in terms of performance enhancement, lifespan extension, energy losses, and thermal management.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102270"},"PeriodicalIF":4.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Engineered architectured Materials, such as metamaterials with periodic patterns, achieve superior properties compared with their stochastic counterparts, such as the random microstructures found in natural materials. The primary research question focuses on the feasibility of learning advantageous microstructural features from stochastic microstructure samples to facilitate the generative design of periodic microstructures, resulting in unprecedented properties. Instead of relying on brainstorming-based, ad hoc design inspiration approaches, we propose an eXplainable Artificial Intelligence (XAI)-based framework to automatically learn critical features from the exceptional outliers (with respect to properties) in stochastic microstructure samples, enabling the generation of novel periodic microstructure patterns with superior properties. This framework is demonstrated on three benchmark cases: designing 2D cellular metamaterials to maximize stiffness in all directions, to maximize the Poisson’s ratio in all directions, and to minimize the thermal expansion ratio. The effectiveness of the design framework is validated by comparing its novel microstructure designs with known stochastic and periodic microstructure designs in terms of the properties of interest.
{"title":"Automated de novo design of architectured materials: Leveraging eXplainable Artificial Intelligence (XAI) for inspiration from stochastic microstructure outliers","authors":"Zhengkun Feng , Weijun Lei , Leidong Xu , Shikui Chen , Hongyi Xu","doi":"10.1016/j.eml.2024.102269","DOIUrl":"10.1016/j.eml.2024.102269","url":null,"abstract":"<div><div>Engineered architectured Materials, such as metamaterials with periodic patterns, achieve superior properties compared with their stochastic counterparts, such as the random microstructures found in natural materials. The primary research question focuses on the feasibility of learning advantageous microstructural features from stochastic microstructure samples to facilitate the generative design of periodic microstructures, resulting in unprecedented properties. Instead of relying on brainstorming-based, <em>ad hoc</em> design inspiration approaches, we propose an eXplainable Artificial Intelligence (XAI)-based framework to automatically learn critical features from the exceptional outliers (with respect to properties) in stochastic microstructure samples, enabling the generation of novel periodic microstructure patterns with superior properties. This framework is demonstrated on three benchmark cases: designing 2D cellular metamaterials to maximize stiffness in all directions, to maximize the Poisson’s ratio in all directions, and to minimize the thermal expansion ratio. The effectiveness of the design framework is validated by comparing its novel microstructure designs with known stochastic and periodic microstructure designs in terms of the properties of interest.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102269"},"PeriodicalIF":4.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.eml.2024.102273
Qian Cong , Dexue Zhang , Jin Xu , Tingkun Chen , Jingfu Jin , Chaozong Liu
Based on the observed micromorphology of the Sinogastromyzon szechuanensis, a groove morphology was designed on the sucker working surface. The length, width, and number of the grooved morphology were selected as the design factors for the bionic morphology. The bionic and standard sucker was fabricated using the mold method, and the sucker adsorption performance was tested. Compared to the standard sucker adsorption force on the substrate (33.20 N), the bio-inspired sucker adsorption force could increase by a maximum of 71.22 %. The change law of the adsorption force was the same as the change law of negative pressure holding time. The bionic sucker could form multiple micro-sealing cavities from the groove morphology while forming a normal sealing cavity with the substrate. The bionic sucker adsorption force was greater than that of the standard sucker. As the length and width of the groove increased, the micro-sealing cavity formed by the groove shape made it difficult to form micro-suckers during the adsorption process, and the adsorption force was affected. With the increase in the number of grooves, the number of micro-suckers formed between the morphology and the substrate during the adsorption process could increase, and the adsorption force was increased.
{"title":"Design the bionic sucker with high adsorption performance based on Sinogastromyzon szechuanensis","authors":"Qian Cong , Dexue Zhang , Jin Xu , Tingkun Chen , Jingfu Jin , Chaozong Liu","doi":"10.1016/j.eml.2024.102273","DOIUrl":"10.1016/j.eml.2024.102273","url":null,"abstract":"<div><div>Based on the observed micromorphology of the <em>Sinogastromyzon szechuanensis</em>, a groove morphology was designed on the sucker working surface. The length, width, and number of the grooved morphology were selected as the design factors for the bionic morphology. The bionic and standard sucker was fabricated using the mold method, and the sucker adsorption performance was tested. Compared to the standard sucker adsorption force on the substrate (33.20 N), the bio-inspired sucker adsorption force could increase by a maximum of 71.22 %. The change law of the adsorption force was the same as the change law of negative pressure holding time. The bionic sucker could form multiple micro-sealing cavities from the groove morphology while forming a normal sealing cavity with the substrate. The bionic sucker adsorption force was greater than that of the standard sucker. As the length and width of the groove increased, the micro-sealing cavity formed by the groove shape made it difficult to form micro-suckers during the adsorption process, and the adsorption force was affected. With the increase in the number of grooves, the number of micro-suckers formed between the morphology and the substrate during the adsorption process could increase, and the adsorption force was increased.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102273"},"PeriodicalIF":4.3,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.eml.2024.102261
Youdong Duan , Lei Zhang , Yonghui Zhang , Linlin Geng , Qiuquan Guo , Jun Yang , Gengkai Hu , Xiaoming Zhou
Dynamic encircling of an anti-parity-time (anti-PT) symmetric exceptional point (EP) leads to chiral transfer of symmetry-broken modes, which has been explored in various systems except acoustics. In this work, acoustic counterpart of this behavior is numerically demonstrated in coupled waveguide systems with anti-PT-symmetric EPs. The model consists of three coupled waveguides designed to mimic a three-state system that can be described by the coupled mode theory. By adiabatically eliminating the intermediate state with high loss, the anti-PT symmetry and associated EP can be formed in an effective system comprising the remaining two states. According to the parametric path enclosing the EP, acoustic propagation model is designed to support the space-driven acoustic mode evolution. Numerical simulations are conducted to demonstrate acoustic chiral transfer of symmetry-broken states.
反奇偶性时间（anti-PT）对称例外点（EP）的动态环绕会导致对称破缺模式的手性转移，这已在除声学之外的各种系统中进行了探索。在这项工作中，在具有反PT 对称例外点的耦合波导系统中，这种行为的声学对应物得到了数值证明。该模型由三个耦合波导组成，旨在模拟可由耦合模式理论描述的三态系统。通过绝热消除具有高损耗的中间状态，反PT 对称性和相关 EP 可以在由其余两个状态组成的有效系统中形成。根据包围 EP 的参数路径，设计了声学传播模型，以支持空间驱动的声学模式演化。数值模拟证明了对称性断裂态的声学手性传递。
{"title":"Acoustic chiral mode transfer for symmetry-broken states in anti-parity-time symmetric systems","authors":"Youdong Duan , Lei Zhang , Yonghui Zhang , Linlin Geng , Qiuquan Guo , Jun Yang , Gengkai Hu , Xiaoming Zhou","doi":"10.1016/j.eml.2024.102261","DOIUrl":"10.1016/j.eml.2024.102261","url":null,"abstract":"<div><div>Dynamic encircling of an anti-parity-time (anti-PT) symmetric exceptional point (EP) leads to chiral transfer of symmetry-broken modes, which has been explored in various systems except acoustics. In this work, acoustic counterpart of this behavior is numerically demonstrated in coupled waveguide systems with anti-PT-symmetric EPs. The model consists of three coupled waveguides designed to mimic a three-state system that can be described by the coupled mode theory. By adiabatically eliminating the intermediate state with high loss, the anti-PT symmetry and associated EP can be formed in an effective system comprising the remaining two states. According to the parametric path enclosing the EP, acoustic propagation model is designed to support the space-driven acoustic mode evolution. Numerical simulations are conducted to demonstrate acoustic chiral transfer of symmetry-broken states.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102261"},"PeriodicalIF":4.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.eml.2024.102260
Helen Le Clézio , Konstantinos Karapiperis , Dennis M. Kochmann
We introduce an efficient computational framework for the simulation of complex beam networks and architected materials. At its core stands a thermodynamics-informed neural network, which serves as a surrogate material model for the cross-sectional response of hyperelastic, slender beams with varying cross-sectional sizes and geometries. The beam description relies on a formal asymptotic expansion from 3D elasticity, which decomposes the problem into an efficient macroscale simulation of the beam’s centerline and a finite elasticity problem on the cross-section (microscale) at each point along the beam. From the solution on the microscale, an effective energy is passed to the macroscale simulation, where it serves as the material model. We introduce a Sobolev-trained neural network as a surrogate model to approximate the effective energy of the microscale. We compare three different neural network architectures, viz. two well established Multi-Layer Perceptron based approaches — a simple feedforward neural network (FNN) and a partially input convex neural network (PICNN) — as well as a recently proposed Kolmogorov-Arnold (KAN) network, and we evaluate their suitability. The models are trained on varying cross-sectional geometries, particularly interpolating between square, circular, and triangular cross-sections, all of varying sizes and degrees of hollowness. Based on its smooth and accurate prediction of the energy landscape, which allows for automatic differentiation, the KAN model was chosen as the surrogate material model, whose effectiveness we demonstrate in a suite of examples, ranging from cantilever beams to 3D beam networks and architected materials. The surrogate model also shows excellent extrapolation capabilities to load cases outside the training dataset.
我们介绍了一种用于模拟复杂梁网络和结构材料的高效计算框架。该框架的核心是一个热力学信息神经网络，它是具有不同横截面尺寸和几何形状的超弹性细长梁横截面响应的替代材料模型。梁的描述依赖于三维弹性的形式渐近展开，它将问题分解为梁中心线的高效宏观模拟和沿梁各点横截面（微观）的有限弹性问题。根据微观尺度上的求解，有效能量被传递到宏观尺度模拟中，作为材料模型。我们引入 Sobolev 训练的神经网络作为近似微尺度有效能量的代理模型。我们比较了三种不同的神经网络架构，即两种成熟的基于多层感知器的方法--简单前馈神经网络（FNN）和部分输入凸神经网络（PICNN）--以及最近提出的 Kolmogorov-Arnold (KAN) 网络，并评估了它们的适用性。这些模型在不同的横截面几何形状上进行了训练，特别是在方形、圆形和三角形横截面之间进行插值，所有横截面的尺寸和空洞程度都各不相同。由于 KAN 模型能平滑、准确地预测能量分布，并能自动进行区分，因此被选为代用材料模型。代用模型还对训练数据集之外的载荷情况显示出卓越的外推能力。
{"title":"Nonlinear two-scale beam simulations accelerated by thermodynamics-informed neural networks","authors":"Helen Le Clézio , Konstantinos Karapiperis , Dennis M. Kochmann","doi":"10.1016/j.eml.2024.102260","DOIUrl":"10.1016/j.eml.2024.102260","url":null,"abstract":"<div><div>We introduce an efficient computational framework for the simulation of complex beam networks and architected materials. At its core stands a thermodynamics-informed neural network, which serves as a surrogate material model for the cross-sectional response of hyperelastic, slender beams with varying cross-sectional sizes and geometries. The beam description relies on a formal asymptotic expansion from 3D elasticity, which decomposes the problem into an efficient macroscale simulation of the beam’s centerline and a finite elasticity problem on the cross-section (microscale) at each point along the beam. From the solution on the microscale, an effective energy is passed to the macroscale simulation, where it serves as the material model. We introduce a Sobolev-trained neural network as a surrogate model to approximate the effective energy of the microscale. We compare three different neural network architectures, viz. two well established Multi-Layer Perceptron based approaches — a simple feedforward neural network (FNN) and a partially input convex neural network (PICNN) — as well as a recently proposed Kolmogorov-Arnold (KAN) network, and we evaluate their suitability. The models are trained on varying cross-sectional geometries, particularly interpolating between square, circular, and triangular cross-sections, all of varying sizes and degrees of hollowness. Based on its smooth and accurate prediction of the energy landscape, which allows for automatic differentiation, the KAN model was chosen as the surrogate material model, whose effectiveness we demonstrate in a suite of examples, ranging from cantilever beams to 3D beam networks and architected materials. The surrogate model also shows excellent extrapolation capabilities to load cases outside the training dataset.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102260"},"PeriodicalIF":4.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1016/j.eml.2024.102268
Cagan Diyaroglu , Rebecca Villanueva , Umar Raza , Selda Oterkus , Erkan Oterkus , Kyungjin Kim
This paper presents a comprehensive experimental and computational study to explore the damage evolution mechanisms of polymer matrix nanocomposite films consisting of rigid ceramic fillers coated on a polymer substrate. The weight ratio of montmorillonite (MMT) fillers in the polyvinyl alcohol (PVA) matrix ranges from 30 % to 70 %, and these are applied onto a polyethylene terephthalate (PET) substrate. Through experiments, apart from damage behaviors, the water vapor transmission rates are also measured to gain insight into moisture diffusion characteristics with varying weight ratios of fillers. The optimal weight ratio of nanocomposite films consisting of a PVA matrix with MMT fillers can vary depending on the purpose of damage resistance and moisture barrier characteristics. A peridynamic theory is employed to simulate various damage scenarios of bi-layer nanocomposite films. The solution strategy presented incorporates the use of the cut-boundary and finite element methods to reduce substrate thickness and make initial predictions of crack onset strains, respectively, under quasi-static loading conditions. Several damage scenarios are considered for thin and thick PVA films on the PET substrate, as well as weak to strong interfaces between the PET-PVA and PVA-MMT layers. Additionally, different distributions of MMT fillers are also considered by varying the distances between them and inserting inclusions. The peridynamic damage analyses encompass crack initiation, propagation, and final failure stages across a wide range of strains, including various damage modes such as matrix cracking, cracking at the filler-matrix, or matrix-substrate interfaces, leading to the cohesive film cracking and delamination.
{"title":"Full range fragmentation simulation of nanoflake filler-matrix composite coatings on a polymer substrate","authors":"Cagan Diyaroglu , Rebecca Villanueva , Umar Raza , Selda Oterkus , Erkan Oterkus , Kyungjin Kim","doi":"10.1016/j.eml.2024.102268","DOIUrl":"10.1016/j.eml.2024.102268","url":null,"abstract":"<div><div>This paper presents a comprehensive experimental and computational study to explore the damage evolution mechanisms of polymer matrix nanocomposite films consisting of rigid ceramic fillers coated on a polymer substrate. The weight ratio of montmorillonite (MMT) fillers in the polyvinyl alcohol (PVA) matrix ranges from 30 % to 70 %, and these are applied onto a polyethylene terephthalate (PET) substrate. Through experiments, apart from damage behaviors, the water vapor transmission rates are also measured to gain insight into moisture diffusion characteristics with varying weight ratios of fillers. The optimal weight ratio of nanocomposite films consisting of a PVA matrix with MMT fillers can vary depending on the purpose of damage resistance and moisture barrier characteristics. A peridynamic theory is employed to simulate various damage scenarios of bi-layer nanocomposite films. The solution strategy presented incorporates the use of the cut-boundary and finite element methods to reduce substrate thickness and make initial predictions of crack onset strains, respectively, under quasi-static loading conditions. Several damage scenarios are considered for thin and thick PVA films on the PET substrate, as well as weak to strong interfaces between the PET-PVA and PVA-MMT layers. Additionally, different distributions of MMT fillers are also considered by varying the distances between them and inserting inclusions. The peridynamic damage analyses encompass crack initiation, propagation, and final failure stages across a wide range of strains, including various damage modes such as matrix cracking, cracking at the filler-matrix, or matrix-substrate interfaces, leading to the cohesive film cracking and delamination.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102268"},"PeriodicalIF":4.3,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.eml.2024.102259
Claudio Boni , Laura Galuppi
Thanks to the extreme deformability, low weight and high strength, thin elements, such as glass/carbon fiber composites shells, or chemically-strengthened glass laminae, are increasingly used for different engineering applications, ranging from deployable space structures and adaptive surfaces for architecture, to flexible electronics and wearable devices. Since an accurate design must be based on reliable values of the material strength, many research efforts have been made in recent years to propose innovative methods specifically devoted to the evaluation of the bending response of highly deformable elements. One of the most reliable procedures seems to be the clamp bending test, originally proposed for thin glass elements. The test consists in prescribing a rotation on two opposite edges of a rectangular thin plate, while adjusting the distance between the supports so to obtain a deformation into an arc of circle. If, from the analytical point of view, this is very effective because it allows to determine the material strength by using very simple formulae, from the practical point of view, its major limitation is that it requires to synchronize the motors and actuators governing the motion of translational and rotational degrees of freedom. Here, an innovative design is presented, characterized by a mechanical/kinematic interconnection between translation and rotation, so that it is possible to perform a clamp bending test in extremely large deformations by controlling just one degree of freedom, i.e., using only one actuator.
{"title":"A kinematics-based single-actuator setup for constant-curvature bending tests in extremely large deformations","authors":"Claudio Boni , Laura Galuppi","doi":"10.1016/j.eml.2024.102259","DOIUrl":"10.1016/j.eml.2024.102259","url":null,"abstract":"<div><div>Thanks to the extreme deformability, low weight and high strength, thin elements, such as glass/carbon fiber composites shells, or chemically-strengthened glass laminae, are increasingly used for different engineering applications, ranging from deployable space structures and adaptive surfaces for architecture, to flexible electronics and wearable devices. Since an accurate design must be based on reliable values of the material strength, many research efforts have been made in recent years to propose innovative methods specifically devoted to the evaluation of the bending response of highly deformable elements. One of the most reliable procedures seems to be the <em>clamp bending</em> test, originally proposed for thin glass elements. The test consists in prescribing a rotation on two opposite edges of a rectangular thin plate, while adjusting the distance between the supports so to obtain a deformation into an arc of circle. If, from the analytical point of view, this is very effective because it allows to determine the material strength by using very simple formulae, from the practical point of view, its major limitation is that it requires to synchronize the motors and actuators governing the motion of translational and rotational degrees of freedom. Here, an innovative design is presented, characterized by a mechanical/kinematic interconnection between translation and rotation, so that it is possible to perform a clamp bending test in extremely large deformations by controlling just one degree of freedom, i.e., using only one actuator.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102259"},"PeriodicalIF":4.3,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.eml.2024.102266
Junwei Pan, Marco Meloni, Seung Deog Kim, Qian Zhang, Jianguo Cai
Kirigami metamaterials, inspired by the ancient art of kirigami, have recently emerged as an innovative approach for creating metamaterials with a diverse range of properties. While many studies on 2D kirigami have focused on stretchability and multi-stable properties, the variation in aperture size throughout the unfolding process of kirigami is another significant geometric feature. In this study, two novel kirigami materials are introduced, based on the topological construction of traditional triangular kirigami designs. These novel kirigami materials exhibit a wide range of aperture sizes, offering significant flexibility and tunability in stretch ratio. The diverse range of aperture sizes presents numerous potential applications at both micro and macro scales. Additionally, a hollow technique is proposed for designing kirigami cellular structures, which undergo distinct stages during the compression process characterized by low-reaction response and high-reaction response. This research expands the design possibilities of kirigami metamaterials by enabling precise adjustments in aperture sizes.
{"title":"Aperture size control in kirigami metamaterials: Towards enhanced performance and applications","authors":"Junwei Pan, Marco Meloni, Seung Deog Kim, Qian Zhang, Jianguo Cai","doi":"10.1016/j.eml.2024.102266","DOIUrl":"10.1016/j.eml.2024.102266","url":null,"abstract":"<div><div>Kirigami metamaterials, inspired by the ancient art of kirigami, have recently emerged as an innovative approach for creating metamaterials with a diverse range of properties. While many studies on 2D kirigami have focused on stretchability and multi-stable properties, the variation in aperture size throughout the unfolding process of kirigami is another significant geometric feature. In this study, two novel kirigami materials are introduced, based on the topological construction of traditional triangular kirigami designs. These novel kirigami materials exhibit a wide range of aperture sizes, offering significant flexibility and tunability in stretch ratio. The diverse range of aperture sizes presents numerous potential applications at both micro and macro scales. Additionally, a hollow technique is proposed for designing kirigami cellular structures, which undergo distinct stages during the compression process characterized by low-reaction response and high-reaction response. This research expands the design possibilities of kirigami metamaterials by enabling precise adjustments in aperture sizes.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102266"},"PeriodicalIF":4.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.eml.2024.102264
Yao Yao , Guanghui Li , Xin Ning
This work introduces a concept of highly shape-morphable macro-scale origami electronic membranes based on the design and fabrication of flexible electronics and engineering origami. The origami electronic membranes can change shapes, provide multi-modal mechanical and environmental sensing capabilities in room and harsh temperatures, and/or switch functions by mechanical shape reconfiguration. This paper presents the materials, design, and fabrication methods for realizing six origami electronic membranes capable of reconfiguring planar or three-dimensional shapes based on the modified flasher, Kresling, Miura-ori, circular, letter, and Tachi-Miura origami patterns. They can be folded into small, stowed geometries and controllably deployed into larger areas or volumes to cover expanded spaces for spatial sensing, enabling significant shape adaptability for flexible electronics beyond simple stretching or bending. The mechanical and environmental sensing modalities include measuring motions, mechanical strains, temperatures, UV light, and humidity. The results reported here may expand the use of flexible electronics to applications that especially require aggressive shape transitions between a small, folded geometry and a large surface or volume such as deployable sensing systems for space explorations and accessing and monitoring highly confined locations.
{"title":"Origami electronic membranes as highly shape-morphable mechanical and environmental sensing systems","authors":"Yao Yao , Guanghui Li , Xin Ning","doi":"10.1016/j.eml.2024.102264","DOIUrl":"10.1016/j.eml.2024.102264","url":null,"abstract":"<div><div>This work introduces a concept of highly shape-morphable macro-scale origami electronic membranes based on the design and fabrication of flexible electronics and engineering origami. The origami electronic membranes can change shapes, provide multi-modal mechanical and environmental sensing capabilities in room and harsh temperatures, and/or switch functions by mechanical shape reconfiguration. This paper presents the materials, design, and fabrication methods for realizing six origami electronic membranes capable of reconfiguring planar or three-dimensional shapes based on the modified flasher, Kresling, Miura-ori, circular, letter, and Tachi-Miura origami patterns. They can be folded into small, stowed geometries and controllably deployed into larger areas or volumes to cover expanded spaces for spatial sensing, enabling significant shape adaptability for flexible electronics beyond simple stretching or bending. The mechanical and environmental sensing modalities include measuring motions, mechanical strains, temperatures, UV light, and humidity. The results reported here may expand the use of flexible electronics to applications that especially require aggressive shape transitions between a small, folded geometry and a large surface or volume such as deployable sensing systems for space explorations and accessing and monitoring highly confined locations.</div></div>","PeriodicalId":56247,"journal":{"name":"Extreme Mechanics Letters","volume":"73 ","pages":"Article 102264"},"PeriodicalIF":4.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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