Pub Date : 2025-12-10DOI: 10.1088/1748-3190/ae2b18
Gargi Das, Alhim Adonai Vera Gonzalez, Daegyun Choi, Anirudh Chhabra, Donghoon Kim, Bruce C Jayne
Lizards are among the most biomechanically versatile animals, exhibiting a broad range of physical and behavioral adaptations, such as adhesion, agile locomotion, vertical climbing, righting reflexes, and various tail-assisted aerial maneuvers. These features have inspired a growing body of biomimetic technologies spanning robotics, medical devices, and control algorithms. This survey provides a comprehensive overview of lizard-inspired design principles and their applications in engineering systems. Starting from biological foundations, we review key physical and behavioral traits and map them to their engineered analogs, including soft adhesion mechanisms, metaheuristic control algorithms, and multi-modal locomotion systems. Special attention is given to lizard righting strategies in the development of self-righting robotic platforms. The survey also extends to the extraterrestrial relevance of lizard-inspired systems, highlighting studies of lizard behavior under altered gravity conditions. Applications in space robotics are explored through gecko-inspired adhesive grippers, locomotion analogies for planetary rovers, and dynamic parallels between lizard biomechanics and free-floating space manipulators. Despite the growing body of work, a comprehensive synthesis uniting terrestrial and extraterrestrial biomimetic insights has been lacking. This review aims to bridge that gap by mapping the trajectory of lizard-inspired biomechanics from biological foundations to robotic implementations, highlighting key achievements, interdisciplinary linkages, and frontiers for future exploration.
{"title":"From Nature to Robots: A Comprehensive Survey on Lizard-Inspired Robotics for Ground and Space Exploration.","authors":"Gargi Das, Alhim Adonai Vera Gonzalez, Daegyun Choi, Anirudh Chhabra, Donghoon Kim, Bruce C Jayne","doi":"10.1088/1748-3190/ae2b18","DOIUrl":"10.1088/1748-3190/ae2b18","url":null,"abstract":"<p><p>Lizards are among the most biomechanically versatile animals, exhibiting a broad range of physical and behavioral adaptations, such as adhesion, agile locomotion, vertical climbing, righting reflexes, and various tail-assisted aerial maneuvers. These features have inspired a growing body of biomimetic technologies spanning robotics, medical devices, and control algorithms. This survey provides a comprehensive overview of lizard-inspired design principles and their applications in engineering systems. Starting from biological foundations, we review key physical and behavioral traits and map them to their engineered analogs, including soft adhesion mechanisms, metaheuristic control algorithms, and multi-modal locomotion systems. Special attention is given to lizard righting strategies in the development of self-righting robotic platforms. The survey also extends to the extraterrestrial relevance of lizard-inspired systems, highlighting studies of lizard behavior under altered gravity conditions. Applications in space robotics are explored through gecko-inspired adhesive grippers, locomotion analogies for planetary rovers, and dynamic parallels between lizard biomechanics and free-floating space manipulators. Despite the growing body of work, a comprehensive synthesis uniting terrestrial and extraterrestrial biomimetic insights has been lacking. This review aims to bridge that gap by mapping the trajectory of lizard-inspired biomechanics from biological foundations to robotic implementations, highlighting key achievements, interdisciplinary linkages, and frontiers for future exploration.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145726912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Origami-inspired folding enables structures to achieve multiple stable configurations, but predicting and controlling these states remain challenging. In nature, insects such as the earwig (Forficula auricularia) utilize non-Euclidean folding principles, leveraging asymmetric resilin-rich creases for compact storage and rapid deployment. Inspired by this, we investigate the bistable and multi-stable behavior of origami-inspired eggbox and saddle units, focusing on how mirroring configurations dictate stability. Through analytical energy modeling and experiments, we confirm that bistability in single units arises from a dominant folding (dihedral) angle-similar to the primary hinge regulation in earwig wings-enabling single-input actuation. In two-unit assemblies, mirroring along the dominant fold axis enforces synchronized snap-through, yielding a coupled bistable system, whereas mirroring along a secondary axis allows independent flipping, resulting in four stable states. Building upon this bioinspired principle, we extend the design to incorporate both deficit and redundant angles while maintaining a symmetric folding scheme, offering a systematic approach to programming multi-stability in origami-based structures. These findings provide a bioinspired strategy for programming multi-stable origami structures through geometric constraints and mirroring. The ability to toggle between synchronized and independent snap-through simplifies control and enables shape transformations without continuous actuation. This approach has broad applications in deployable structures, bioinspired soft robotics, and adaptive materials, leveraging multi-stability for efficient morphing.
{"title":"Earwig wing-inspired bistable origami: non-Euclidean units with soft joints.","authors":"Yuanyuan Li, Yao Qu, Xiaohui Zhang, Qian Zhang, Jian Feng, Jianguo Cai, Cecilia Laschi","doi":"10.1088/1748-3190/ae224e","DOIUrl":"10.1088/1748-3190/ae224e","url":null,"abstract":"<p><p>Origami-inspired folding enables structures to achieve multiple stable configurations, but predicting and controlling these states remain challenging. In nature, insects such as the earwig (<i>Forficula auricularia</i>) utilize non-Euclidean folding principles, leveraging asymmetric resilin-rich creases for compact storage and rapid deployment. Inspired by this, we investigate the bistable and multi-stable behavior of origami-inspired eggbox and saddle units, focusing on how mirroring configurations dictate stability. Through analytical energy modeling and experiments, we confirm that bistability in single units arises from a dominant folding (dihedral) angle-similar to the primary hinge regulation in earwig wings-enabling single-input actuation. In two-unit assemblies, mirroring along the dominant fold axis enforces synchronized snap-through, yielding a coupled bistable system, whereas mirroring along a secondary axis allows independent flipping, resulting in four stable states. Building upon this bioinspired principle, we extend the design to incorporate both deficit and redundant angles while maintaining a symmetric folding scheme, offering a systematic approach to programming multi-stability in origami-based structures. These findings provide a bioinspired strategy for programming multi-stable origami structures through geometric constraints and mirroring. The ability to toggle between synchronized and independent snap-through simplifies control and enables shape transformations without continuous actuation. This approach has broad applications in deployable structures, bioinspired soft robotics, and adaptive materials, leveraging multi-stability for efficient morphing.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145566424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-28DOI: 10.1088/1748-3190/ae1e4b
Nnamdi C Chikere, Sofia Lozano Voticky, Quang D Tran, Yasemin Ozkan-Aydin
Traditional locomotion strategies fail in low-Reynolds-number fluid environments, where viscous forces dominate over inertial forces. Microorganisms have developed specialized structures such as cilia and flagella to overcome this challenge, enabling efficient movement through highly resistive environments. Among these organisms,Phytophthorazoospores demonstrate unique locomotion mechanisms that allow them to rapidly spread and attack new hosts while expending minimal energy. In this study, we present the design, fabrication, and testing of a zoospore-inspired robot, which leverages dual flexible planar flagella and oscillatory propulsion mechanisms to emulate the natural swimming behavior of zoospores. Our experiments and theoretical model reveal that both flagellar shape and oscillation frequency strongly influence the robot's propulsion speed, with longer flagella and higher frequencies yielding enhanced performance. Additionally, the anterior flagellum, which generates a pulling force on the body, is dominant in enhancing propulsion efficiency compared to the posterior flagellum's pushing force. This is a significant experimental finding, as it would be challenging to observe directly in biological zoospores, which spontaneously release the posterior flagellum when the anterior flagellum detaches. This work contributes to the development of advanced microscale robotic systems with potential applications in medical, environmental, and industrial fields. It also provides a valuable platform for studying biological zoospores and their unique locomotion strategies.
{"title":"Flagellar swimming at low Reynolds numbers: zoospore-inspired robotic swimmers with dual flagella for high-speed locomotion.","authors":"Nnamdi C Chikere, Sofia Lozano Voticky, Quang D Tran, Yasemin Ozkan-Aydin","doi":"10.1088/1748-3190/ae1e4b","DOIUrl":"10.1088/1748-3190/ae1e4b","url":null,"abstract":"<p><p>Traditional locomotion strategies fail in low-Reynolds-number fluid environments, where viscous forces dominate over inertial forces. Microorganisms have developed specialized structures such as cilia and flagella to overcome this challenge, enabling efficient movement through highly resistive environments. Among these organisms,<i>Phytophthora</i>zoospores demonstrate unique locomotion mechanisms that allow them to rapidly spread and attack new hosts while expending minimal energy. In this study, we present the design, fabrication, and testing of a zoospore-inspired robot, which leverages dual flexible planar flagella and oscillatory propulsion mechanisms to emulate the natural swimming behavior of zoospores. Our experiments and theoretical model reveal that both flagellar shape and oscillation frequency strongly influence the robot's propulsion speed, with longer flagella and higher frequencies yielding enhanced performance. Additionally, the anterior flagellum, which generates a pulling force on the body, is dominant in enhancing propulsion efficiency compared to the posterior flagellum's pushing force. This is a significant experimental finding, as it would be challenging to observe directly in biological zoospores, which spontaneously release the posterior flagellum when the anterior flagellum detaches. This work contributes to the development of advanced microscale robotic systems with potential applications in medical, environmental, and industrial fields. It also provides a valuable platform for studying biological zoospores and their unique locomotion strategies.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145497593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-27DOI: 10.1088/1748-3190/ae1fc7
Hanghao Zhao, Zhimeng Zhang, Chunning Ji, Xianghe Li
Harbour seal whiskers, characterised by their wavy morphology and elliptical cross-section, are capable of perceiving minute flow velocities as low as 10-4m s-1. This study investigates the hydrodynamics and flow perception mechanisms of three elastically mounted whiskers arranged side-by-side in the wake of a caudal fin, using direct numerical simulations. The whiskers are spaced at centre-to-centre distances ofS/D= 2-4, whereSis the inter-whisker spacing andDis the equivalent narrow-face diameter of whisker model. The vibration responses, hydrodynamic forces, wake patterns, energy transfer mechanisms, and flow-sensing performance of the whiskers were analysed. Two distinct wake-whisker interaction patterns are identified, governed by the side-by-side spacing: (Ⅰ) partially-interacted pattern (S/D⩽ 2), in which the upstream caudal fin vortexes bypass the side whiskers, leading to a direct impact on the side whiskers only; (Ⅱ) fully-interacted pattern (S/D> 2), in which the vortexes are able to pass through the gap between the whiskers, allowing all three whiskers to interact with the wake. The energy transfer analysis reveals that the spanwise and chordwise vortexes of caudal fin selectively enhance or suppress whisker vibrations depending on their relative rotation directions, leading to distinct excitation patterns across different spacing configurations. An optimal wake flow perception is achieved atS/D= 3 through lift-vorticity correlation and mutual information analyses under the studied conditions.
{"title":"Hydrodynamics and flow perception mechanism of side-by-side Harbour seal whiskers in wake flow.","authors":"Hanghao Zhao, Zhimeng Zhang, Chunning Ji, Xianghe Li","doi":"10.1088/1748-3190/ae1fc7","DOIUrl":"10.1088/1748-3190/ae1fc7","url":null,"abstract":"<p><p>Harbour seal whiskers, characterised by their wavy morphology and elliptical cross-section, are capable of perceiving minute flow velocities as low as 10<sup>-4</sup>m s<sup>-1</sup>. This study investigates the hydrodynamics and flow perception mechanisms of three elastically mounted whiskers arranged side-by-side in the wake of a caudal fin, using direct numerical simulations. The whiskers are spaced at centre-to-centre distances of<i>S</i>/<i>D</i>= 2-4, where<i>S</i>is the inter-whisker spacing and<i>D</i>is the equivalent narrow-face diameter of whisker model. The vibration responses, hydrodynamic forces, wake patterns, energy transfer mechanisms, and flow-sensing performance of the whiskers were analysed. Two distinct wake-whisker interaction patterns are identified, governed by the side-by-side spacing: (Ⅰ) partially-interacted pattern (<i>S</i>/<i>D</i>⩽ 2), in which the upstream caudal fin vortexes bypass the side whiskers, leading to a direct impact on the side whiskers only; (Ⅱ) fully-interacted pattern (<i>S</i>/<i>D</i>> 2), in which the vortexes are able to pass through the gap between the whiskers, allowing all three whiskers to interact with the wake. The energy transfer analysis reveals that the spanwise and chordwise vortexes of caudal fin selectively enhance or suppress whisker vibrations depending on their relative rotation directions, leading to distinct excitation patterns across different spacing configurations. An optimal wake flow perception is achieved at<i>S</i>/<i>D</i>= 3 through lift-vorticity correlation and mutual information analyses under the studied conditions.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145524897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1088/1748-3190/ae0dd0
Zhanhong Guo, Na Han, Meng Zou, Yansong Liu, Jing Liu
The multi-scale hierarchical structure of the conch shell exhibits exceptional mechanical properties, earning it the reputation as nature's natural armor. Based on structural bionics, this study investigates the self-similar three-dimensional structure of conch shells and analyzes their effects on energy absorption (EA). The universal testing machine results demonstrate that the shell specimens exhibit distinct mechanical properties under different loading conditions. Under transverse compression testing, the gastropod shells showed an average peak load of 442.55 N, compressive strength of 110.62 MPa, and Young's modulus of 13.36 GPa. In axial compression tests, the shells displayed an average peak load of 412.16 N with a mean crushing force of 219.79 N. A mathematical 3D model of the conch was developed based on geometric formulas, complemented by scanner-based sample digitization and reverse reconstruction. Multiphysics simulation tools enabled optimization of key conch topology parameters (α,β,r0,a,b), while response surface modeling quantified parameter-EA correlations. The optimized structural parameters were determined asα= 86.6,β= 12.2,r0= 92.5,a= 27.5,b= 37.5.The performance metrics of this structure are as follows: SEAoptim= 13.38 J g-1, MCFoptim= 13.08 kN, CFEoptim= 0.45, and ULCoptim= 0.33.Our findings establish that energy dissipation performance in conch shells is fundamentally linked to their fractal-like self-similar organization. These findings provide crucial theoretical foundations and experimental references for the optimized design of bio-inspired energy-absorbing structures.
{"title":"Mechanical properties and energy absorption characteristics of the self-similar structure in spiral shells.","authors":"Zhanhong Guo, Na Han, Meng Zou, Yansong Liu, Jing Liu","doi":"10.1088/1748-3190/ae0dd0","DOIUrl":"10.1088/1748-3190/ae0dd0","url":null,"abstract":"<p><p>The multi-scale hierarchical structure of the conch shell exhibits exceptional mechanical properties, earning it the reputation as nature's natural armor. Based on structural bionics, this study investigates the self-similar three-dimensional structure of conch shells and analyzes their effects on energy absorption (EA). The universal testing machine results demonstrate that the shell specimens exhibit distinct mechanical properties under different loading conditions. Under transverse compression testing, the gastropod shells showed an average peak load of 442.55 N, compressive strength of 110.62 MPa, and Young's modulus of 13.36 GPa. In axial compression tests, the shells displayed an average peak load of 412.16 N with a mean crushing force of 219.79 N. A mathematical 3D model of the conch was developed based on geometric formulas, complemented by scanner-based sample digitization and reverse reconstruction. Multiphysics simulation tools enabled optimization of key conch topology parameters (<i>α</i>,<i>β</i>,<i>r</i><sub>0</sub>,<i>a</i>,<i>b</i>), while response surface modeling quantified parameter-EA correlations. The optimized structural parameters were determined as<i>α</i>= 86.6,<i>β</i>= 12.2,<i>r</i><sub>0</sub>= 92.5,<i>a</i>= 27.5,<i>b</i>= 37.5.The performance metrics of this structure are as follows: SEA<sub>optim</sub>= 13.38 J g<sup>-1</sup>, MCF<sub>optim</sub>= 13.08 kN, CFE<sub>optim</sub>= 0.45, and ULC<sub>optim</sub>= 0.33.Our findings establish that energy dissipation performance in conch shells is fundamentally linked to their fractal-like self-similar organization. These findings provide crucial theoretical foundations and experimental references for the optimized design of bio-inspired energy-absorbing structures.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145202008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bio-robots, a novel type of robot based on a brain-machine interface, have shown great potential in search and rescue tasks. Current research is focused on the bio-robot itself, such as locomotion, localization and navigation, but lacks interactions with the external environment. In this paper we propose a new system that allows a rat robot to autonomously explore the border of an unknown field out of sight and then obtain the boundary map. We invented a wearable backpack, which is an embedded system with laser-ranging sensors, inertial measurement units and an ultra-wide band (UWB) module, for the rat robot. Based on the wearable system, a classification method for motion states based on the random forest algorithm and a navigation algorithm based on a finite state machine were developed for the autonomous exploration of the border and tested in a locomotion experiment. With the localization and distance data from the UWB module and laser-ranging sensors, we mapped the distribution of the border using the Ramber-Douglas-Peucker algorithm. The results show that this system could effectively navigate the rat robot to explore the field and accurately detect the border. The accuracy of classification reaches 97.86% and the error rate of border detection is 5.90%. This work provides a novel technology that has potential for practical applications such as prospecting for minerals and search tasks.
{"title":"Rat robot autonomous border detection based on wearable sensors.","authors":"Haobo Xie, Haoze Xu, Kedi Xu, Chaonan Yu, Wei Yang, Canjun Yang","doi":"10.1088/1748-3190/ae0ee8","DOIUrl":"10.1088/1748-3190/ae0ee8","url":null,"abstract":"<p><p>Bio-robots, a novel type of robot based on a brain-machine interface, have shown great potential in search and rescue tasks. Current research is focused on the bio-robot itself, such as locomotion, localization and navigation, but lacks interactions with the external environment. In this paper we propose a new system that allows a rat robot to autonomously explore the border of an unknown field out of sight and then obtain the boundary map. We invented a wearable backpack, which is an embedded system with laser-ranging sensors, inertial measurement units and an ultra-wide band (UWB) module, for the rat robot. Based on the wearable system, a classification method for motion states based on the random forest algorithm and a navigation algorithm based on a finite state machine were developed for the autonomous exploration of the border and tested in a locomotion experiment. With the localization and distance data from the UWB module and laser-ranging sensors, we mapped the distribution of the border using the Ramber-Douglas-Peucker algorithm. The results show that this system could effectively navigate the rat robot to explore the field and accurately detect the border. The accuracy of classification reaches 97.86% and the error rate of border detection is 5.90%. This work provides a novel technology that has potential for practical applications such as prospecting for minerals and search tasks.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145214591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-24DOI: 10.1088/1748-3190/ae191b
Samuel H Smullen, Ryan St Pierre
Latch-mediated spring actuation systems leverage the interplay of springs and latches to rapidly accelerate a load. In biological systems, elastic energy is often distributed across multiple structures, resulting in forces applied from multiple springs. Here, we specifically examine dual-spring force couples in torque reversal systems. A dual-spring force couple applies forces from recoiling springs at two locations to generate torque. Torque reversal systems transition from spring loading to spring actuation through a change in torque direction. We develop a mathematical model of a dual-spring force couple in a torque reversal system, where one spring is attached to the pivot point of a rigid body. During spring loading, this spring compresses to store elastic energy; during spring actuation, it recoils, driving pivot translation and contributing to rotation. We experimentally validate the model using a physical model. We then vary geometric parameters and the energy partition between the two springs to examine how these factors shape system dynamics. We show how variations in geometry and energy partition influence the rotational, translational and coupling terms in the mathematical model. Finally, we demonstrate that the energetics of these systems must be carefully accounted for to accurately capture how potential energy is transformed into kinetic energy. We hypothesize that dual-spring force couples in torque reversal systems may be prevalent in biological organisms, and that insights from this work can guide the design of spring-actuated mechanisms in robotics.
{"title":"Dynamics and energetics of dual-spring force couples in torque reversal systems.","authors":"Samuel H Smullen, Ryan St Pierre","doi":"10.1088/1748-3190/ae191b","DOIUrl":"10.1088/1748-3190/ae191b","url":null,"abstract":"<p><p>Latch-mediated spring actuation systems leverage the interplay of springs and latches to rapidly accelerate a load. In biological systems, elastic energy is often distributed across multiple structures, resulting in forces applied from multiple springs. Here, we specifically examine dual-spring force couples in torque reversal systems. A dual-spring force couple applies forces from recoiling springs at two locations to generate torque. Torque reversal systems transition from spring loading to spring actuation through a change in torque direction. We develop a mathematical model of a dual-spring force couple in a torque reversal system, where one spring is attached to the pivot point of a rigid body. During spring loading, this spring compresses to store elastic energy; during spring actuation, it recoils, driving pivot translation and contributing to rotation. We experimentally validate the model using a physical model. We then vary geometric parameters and the energy partition between the two springs to examine how these factors shape system dynamics. We show how variations in geometry and energy partition influence the rotational, translational and coupling terms in the mathematical model. Finally, we demonstrate that the energetics of these systems must be carefully accounted for to accurately capture how potential energy is transformed into kinetic energy. We hypothesize that dual-spring force couples in torque reversal systems may be prevalent in biological organisms, and that insights from this work can guide the design of spring-actuated mechanisms in robotics.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145402909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biologically-inspired jumping robots have demonstrated remarkable adaptability in complex environments, making them increasingly valuable across various fields. However, effective path planning in obstacle-dense environments for large-scale jumping robots remains a significant challenge. Inspired by independent decision-making in the efficient collaborative behavior of locust swarms, we propose a two-stage curriculum reinforcement learning (TS-CRL) framework for locust-inspired jumping robots. This framework enables individual robots to autonomously determine actions based on local environmental observations during group crossing tasks. TS-CRL incorporates a population-invariant encoder with an attention mechanism, allowing it to efficiently handle an increased number of training robots. Moreover, it employs an actor-critic network architecture based on Kolmogorov-Arnold networks to enhance training performance. To further improve the training efficiency, we divided the policy training process into two stages with gradually increasing environmental complexity. The effectiveness and scalability of TS-CRL were validated through a locust-inspired jumping robot platform in challenging simulation scenarios. Notably, TS-CRL can generate efficient, collision-free paths to guide multiple jumping robots. Compared with typical reinforcement learning algorithms, TS-CRL reduced the average path cost by 13.7% and markedly improved the success rate of robots in reaching the target areas. Finally, we constructed a multi-robot system consisting of locust-inspired jumping robots for experiments in the real world.
{"title":"Path planning of locust-inspired jumping robots in obstacle-dense environments using curriculum reinforcement learning.","authors":"Qijie Zhou, Gangyang Li, Zhiqiang Yu, Hao Wen, Haibo Luo, Qing Shi","doi":"10.1088/1748-3190/ae1a29","DOIUrl":"10.1088/1748-3190/ae1a29","url":null,"abstract":"<p><p>Biologically-inspired jumping robots have demonstrated remarkable adaptability in complex environments, making them increasingly valuable across various fields. However, effective path planning in obstacle-dense environments for large-scale jumping robots remains a significant challenge. Inspired by independent decision-making in the efficient collaborative behavior of locust swarms, we propose a two-stage curriculum reinforcement learning (TS-CRL) framework for locust-inspired jumping robots. This framework enables individual robots to autonomously determine actions based on local environmental observations during group crossing tasks. TS-CRL incorporates a population-invariant encoder with an attention mechanism, allowing it to efficiently handle an increased number of training robots. Moreover, it employs an actor-critic network architecture based on Kolmogorov-Arnold networks to enhance training performance. To further improve the training efficiency, we divided the policy training process into two stages with gradually increasing environmental complexity. The effectiveness and scalability of TS-CRL were validated through a locust-inspired jumping robot platform in challenging simulation scenarios. Notably, TS-CRL can generate efficient, collision-free paths to guide multiple jumping robots. Compared with typical reinforcement learning algorithms, TS-CRL reduced the average path cost by 13.7% and markedly improved the success rate of robots in reaching the target areas. Finally, we constructed a multi-robot system consisting of locust-inspired jumping robots for experiments in the real world.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145423535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1088/1748-3190/ae0bd8
Reid Wynja, Adrian Carleton, Sudhansh Tanneru, Yahya Modarres-Sadeghi
The Ocean Sunfish (Mola mola) has one of the most unusual body geometries and swimming strategies of all fish species. Effectively lacking a caudal fin, these fish propel themselves by synchronized flapping of their extremely long dorsal and anal fins-a form of locomotion known as median/paired fin (MPF). Long misunderstood to be poor swimmers,Mola molaare increasingly being recognized for their surprising swimming efficiency and agility. MPF propulsion can be modeled as a combination of pitching and heaving in a hydrofoil, a well-studied phenomenon, and the mechanical simplicity of these motions lend themselves well to the creation of compact and robust propulsion systems. Here, we present a novel bio-inspired marine robotic test platform based on the body geometry and swimming strategy of theMola mola. We analyze the forces generated by various flapping frequencies and patterns (synchronous and asynchronous), and the flow behavior for both single flap events and continuous flapping. We observe that there is a linear trend between flapping frequency and thrust force for both synchronous and asynchronous flapping up to the maximum frequencies obtainable with the current design. We then test the flapping parameters resulting in the highest thrust forces for both flapping patterns in a free-swimming arrangement and show that the synchronous flapping results in larger steady-state swimming speed.
{"title":"Mobot mobot: an ocean sunfish (<i>Mola mola</i>) robot.","authors":"Reid Wynja, Adrian Carleton, Sudhansh Tanneru, Yahya Modarres-Sadeghi","doi":"10.1088/1748-3190/ae0bd8","DOIUrl":"10.1088/1748-3190/ae0bd8","url":null,"abstract":"<p><p>The Ocean Sunfish (<i>Mola mola</i>) has one of the most unusual body geometries and swimming strategies of all fish species. Effectively lacking a caudal fin, these fish propel themselves by synchronized flapping of their extremely long dorsal and anal fins-a form of locomotion known as median/paired fin (MPF). Long misunderstood to be poor swimmers,<i>Mola mola</i>are increasingly being recognized for their surprising swimming efficiency and agility. MPF propulsion can be modeled as a combination of pitching and heaving in a hydrofoil, a well-studied phenomenon, and the mechanical simplicity of these motions lend themselves well to the creation of compact and robust propulsion systems. Here, we present a novel bio-inspired marine robotic test platform based on the body geometry and swimming strategy of the<i>Mola mola</i>. We analyze the forces generated by various flapping frequencies and patterns (synchronous and asynchronous), and the flow behavior for both single flap events and continuous flapping. We observe that there is a linear trend between flapping frequency and thrust force for both synchronous and asynchronous flapping up to the maximum frequencies obtainable with the current design. We then test the flapping parameters resulting in the highest thrust forces for both flapping patterns in a free-swimming arrangement and show that the synchronous flapping results in larger steady-state swimming speed.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145152008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-12DOI: 10.1088/1748-3190/ae18a8
Krispin C V Broers, Sophie F Armanini
With the emergence of new flapping-wing micro aerial vehicle (FWMAV) designs, a need for extensive and advanced mission capabilities arises. FWMAVs try to adapt and emulate the flight features of birds and flying insects. While current designs already achieve high manoeuvrability, they still almost entirely lack perching and take-off capabilities. These capabilities would enable long-term monitoring and surveillance operations, and more complex and multifaceted missions in cluttered environments. We present the development and testing of a framework that enables repeatable perching and take-off for small- to medium-sized FWMAVs, utilising soft, non-damaging grippers. Thanks to its novel active-passive actuation system, an energy-conserving state can be achieved and indefinitely maintained while the vehicle is perched. This actuation system is inspired by the digital tendon locking mechanism observed in perching birds and allows for high gripping power and minimal energy usage with a low weight penalty. A prototype of the proposed system weighing under 39 g was manufactured and extensively tested on a 110 g flapping-wing robot. Successful free-flight tests demonstrated the full mission cycle of landing, perching and subsequent take-off. The telemetry data recorded during the flights yields extensive insight into the system's behaviour and is a valuable step towards full automation and optimisation of the entire take-off and landing cycle.
{"title":"Repeatable energy-efficient perching for flapping-wing robots using soft-grippers.","authors":"Krispin C V Broers, Sophie F Armanini","doi":"10.1088/1748-3190/ae18a8","DOIUrl":"10.1088/1748-3190/ae18a8","url":null,"abstract":"<p><p>With the emergence of new flapping-wing micro aerial vehicle (FWMAV) designs, a need for extensive and advanced mission capabilities arises. FWMAVs try to adapt and emulate the flight features of birds and flying insects. While current designs already achieve high manoeuvrability, they still almost entirely lack perching and take-off capabilities. These capabilities would enable long-term monitoring and surveillance operations, and more complex and multifaceted missions in cluttered environments. We present the development and testing of a framework that enables repeatable perching and take-off for small- to medium-sized FWMAVs, utilising soft, non-damaging grippers. Thanks to its novel active-passive actuation system, an energy-conserving state can be achieved and indefinitely maintained while the vehicle is perched. This actuation system is inspired by the digital tendon locking mechanism observed in perching birds and allows for high gripping power and minimal energy usage with a low weight penalty. A prototype of the proposed system weighing under 39 g was manufactured and extensively tested on a 110 g flapping-wing robot. Successful free-flight tests demonstrated the full mission cycle of landing, perching and subsequent take-off. The telemetry data recorded during the flights yields extensive insight into the system's behaviour and is a valuable step towards full automation and optimisation of the entire take-off and landing cycle.</p>","PeriodicalId":55377,"journal":{"name":"Bioinspiration & Biomimetics","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145395258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}