1
|
Zheng C, Ding J, Dong B, Lian G, He K, Xie F. How Non-Uniform Stiffness Affects the Propulsion Performance of a Biomimetic Robotic Fish. Biomimetics (Basel) 2022; 7:biomimetics7040187. [PMID: 36412715 PMCID: PMC9680224 DOI: 10.3390/biomimetics7040187] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/29/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Live fish in nature exhibit various stiffness characteristics. The anguilliform swimmer, like eels, has a relatively flexible body, while the thunniform swimmer, like the swordfishes, has a much stiffer body. Correspondingly, in the design of biomimetic robotic fish, how to balance the non-uniform stiffness to achieve better propulsion performance is an essential question needed to be answered. In this paper, we conduct an experimental study on this question. First, a customized experimental platform is built, which eases the adjustment of the non-uniform stiffness ratio, the stiffness of the flexible part, the flapping frequency, and the flapping amplitude. Second, extensive experiments are carried out, finding that to maximize the propulsion performance of the biomimetic robotic fish, the non-uniform stiffness ratio is required to adapt to different locomotor parameters. Specifically, the non-uniform stiffness ratio needs to be reduced when the robotic fish works at low frequency, and it needs to be increased when the robotic fish works at high frequency. Finally, detailed discussions are given to further analyze the experimental results. Overall, this study can shed light on the design of a non-uniform biomimetic robotic fish, which helps to increase its propulsion performance.
Collapse
Affiliation(s)
- Changzhen Zheng
- School of Artificial Intelligence, Shenzhen Polytechnic, Shenzhen 518055, China
- College of Mechanical Engineering, Guangxi University, Nanning 530004, China
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jiang Ding
- College of Mechanical Engineering, Guangxi University, Nanning 530004, China
| | - Bingbing Dong
- School of Artificial Intelligence, Shenzhen Polytechnic, Shenzhen 518055, China
- College of Mechanical Automation, Wuhan University of Science and Technology, Wuhan 430000, China
| | - Guoyun Lian
- School of Artificial Intelligence, Shenzhen Polytechnic, Shenzhen 518055, China
| | - Kai He
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Fengran Xie
- School of Artificial Intelligence, Shenzhen Polytechnic, Shenzhen 518055, China
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Correspondence: or ; Tel.: +86-130-5205-8323
| |
Collapse
|
2
|
Quinn D, Lauder G. Tunable stiffness in fish robotics: mechanisms and advantages. BIOINSPIRATION & BIOMIMETICS 2021; 17:011002. [PMID: 34814125 DOI: 10.1088/1748-3190/ac3ca5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
One of the emerging themes of fish-inspired robotics is flexibility. Adding flexibility to the body, joints, or fins of fish-inspired robots can significantly improve thrust and/or efficiency during locomotion. However, the optimal stiffness depends on variables such as swimming speed, so there is no one 'best' stiffness that maximizes efficiency in all conditions. Fish are thought to solve this problem by using muscular activity to tune their body and fin stiffness in real-time. Inspired by fish, some recent robots sport polymer actuators, adjustable leaf springs, or artificial tendons that tune stiffness mechanically. Models and water channel tests are providing a theoretical framework for stiffness-tuning strategies that devices can implement. The strategies can be thought of as analogous to car transmissions, which allow users to improve efficiency by tuning gear ratio with driving speed. We provide an overview of the latest discoveries about (1) the propulsive benefits of flexibility, particularlytunableflexibility, and (2) the mechanisms and strategies that fish and fish-inspired robots use to tune stiffness while swimming.
Collapse
Affiliation(s)
- Daniel Quinn
- Mechanical & Aerospace Engineering, University of Virginia, Charlottesville, VA, United States of America
- Electrical & Computer Engineering, University of Virginia, Charlottesville, VA, United States of America
| | - George Lauder
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States of America
| |
Collapse
|
3
|
Hussein AA, Ragab SA, Hajj MR, Patil MJ. Material and geometric effects on propulsion of a fish tail. BIOINSPIRATION & BIOMIMETICS 2021; 16:066008. [PMID: 34450610 DOI: 10.1088/1748-3190/ac220e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
We investigate the effects of material flexibility and aspect ratio on the propulsion of flapping tails. The tail, which is assumed to deform in the bending direction only, is modeled using the Euler-Bernoulli beam theory. The hydrodynamic loads generated by the flapping motion are calculated using the three-dimensional unsteady vortex lattice method. The finite element method is used to solve the coupled time-dependent equations of motion using an implicit solver for time integration. The results show improvement in the thrust and propulsive efficiency over a specific range of non-dimensional flexibility defined by the ratio of the elastic forces to fluid pressure forces. Structural and flow characteristics associated with the improved performance are discussed. As for geometric effects, the performance depends on the excitation frequency. At low frequencies, the improvement is continuous with increasing the aspect ratio in a manner similar to that of rigid tails. At higher frequencies, the improvement is limited to a region defined by aspect ratios that are less than 0.5. The extent of the improvement depends on the flexibility.
Collapse
Affiliation(s)
- Ahmed A Hussein
- Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Saad A Ragab
- Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, United States of America
| | - Muhammad R Hajj
- Civil, Environmental and Ocean Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, United States of America
| | - Mayuresh J Patil
- Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, VA 24061, United States of America
| |
Collapse
|
4
|
Dagenais P, Blanchoud S, Pury D, Pfefferli C, Aegerter-Wilmsen T, Aegerter CM, Jaźwińska A. Hydrodynamic stress and phenotypic plasticity of the zebrafish regenerating fin. J Exp Biol 2021; 224:271142. [PMID: 34338301 DOI: 10.1242/jeb.242309] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/14/2021] [Indexed: 01/23/2023]
Abstract
Understanding how extrinsic factors modulate genetically encoded information to produce a specific phenotype is of prime scientific interest. In particular, the feedback mechanism between abiotic forces and locomotory organs during morphogenesis to achieve efficient movement is a highly relevant example of such modulation. The study of this developmental process can provide unique insights on the transduction of cues at the interface between physics and biology. Here, we take advantage of the natural ability of adult zebrafish to regenerate their amputated fins to assess its morphogenic plasticity upon external modulations. Using a variety of surgical and chemical treatments, we could induce phenotypic responses to the structure of the fin. Through the ablation of specific rays in regenerating caudal fins, we generated artificially narrowed appendages in which the fin cleft depth and the positioning of rays bifurcations were perturbed compared with normal regenerates. To dissect the role of mechanotransduction in this process, we investigated the patterns of hydrodynamic forces acting on the surface of a zebrafish fin during regeneration by using particle tracking velocimetry on a range of biomimetic hydrofoils. This experimental approach enabled us to quantitatively compare hydrodynamic stress distributions over flapping fins of varying sizes and shapes. As a result, viscous shear stress acting on the distal margin of regenerating fins and the resulting internal tension are proposed as suitable signals for guiding the regulation of ray growth dynamics and branching pattern. Our findings suggest that mechanical forces are involved in the fine-tuning of the locomotory organ during fin morphogenesis.
Collapse
Affiliation(s)
- Paule Dagenais
- Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Simon Blanchoud
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - David Pury
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Catherine Pfefferli
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Tinri Aegerter-Wilmsen
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Christof M Aegerter
- Physik-Institut, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.,Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Anna Jaźwińska
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| |
Collapse
|
5
|
Luo Y, Xiao Q, Shi G, Pan G, Chen D. The effect of variable stiffness of tuna-like fish body and fin on swimming performance. BIOINSPIRATION & BIOMIMETICS 2020; 16:016003. [PMID: 33164914 DOI: 10.1088/1748-3190/abb3b6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The work in this paper focuses on the examination of the effect of variable stiffness distributions on the kinematics and propulsion performance of a tuna-like swimmer. This is performed with the use of a recently developed fully coupled fluid-structure interaction solver. The two different scenarios considered in the present study are the stiffness varied along the fish body and the caudal fin, respectively. Our results show that it is feasible to replicate the similar kinematics and propulsive capability to that of the real fish via purely passive structural deformations. In addition, propulsion performance improvement is mainly dependent on the better orientation of the force near the posterior part of swimmers towards the thrust direction. Specifically, when a variable body stiffness scenario is considered, the bionic body stiffness profile results in better performance in most cases studied herein compared with a uniform stiffness commonly investigated in previous studies. Given the second scenario, where the stiffness is varied only in the spanwise direction of the tail, similar tail kinematics to that of the live scombrid fish only occurs in association with the heterocercal flexural rigidity profile. The resulting asymmetric tail conformation also yields performance improvement at intermediate stiffness in comparison to the cupping and uniform stiffness.
Collapse
Affiliation(s)
- Yang Luo
- Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, G4 0LZ, United Kingdom
| | - Qing Xiao
- Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, G4 0LZ, United Kingdom
| | - Guangyu Shi
- Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, G4 0LZ, United Kingdom
| | - Guang Pan
- School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China
| | - Daoyi Chen
- Division of Ocean Science and Technology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, People's Republic of China
| |
Collapse
|
6
|
The Analysis of Biomimetic Caudal Fin Propulsion Mechanism with CFD. Appl Bionics Biomech 2020; 2020:7839049. [PMID: 32676127 PMCID: PMC7333036 DOI: 10.1155/2020/7839049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 01/22/2020] [Accepted: 02/25/2020] [Indexed: 11/29/2022] Open
Abstract
In nature, fish not only have extraordinary ability of underwater movement but also have high mobility and flexibility. The low energy consumption and high efficiency of fish propulsive method provide a new idea for the research of bionic underwater robot and bionic propulsive technology. In this paper, the swordfish was taken as the research object, and the mechanism of the caudal fin propulsion was preliminarily explored by analyzing the flow field structure generated by the swing of caudal fin. Subsequently, the influence of the phase difference of the heaving and pitching movement, the swing amplitude of caudal fin, and Strouhal number (St number) on the propulsion performance of fish was discussed. The results demonstrated that the fish can obtain a greater propulsion force by optimizing the motion parameters of the caudal fin in a certain range. Lastly, through the mathematical model analysis of the tail of the swordfish, the producing propulsive force principle of the caudal fin and the caudal peduncle was obtained. Hence, the proposed method provided a theoretical basis for the design of a high-efficiency bionic propulsion system.
Collapse
|
7
|
Shi G, Xiao Q, Zhu Q, Liao W. Fluid-structure interaction modeling on a 3D ray-strengthened caudal fin. BIOINSPIRATION & BIOMIMETICS 2019; 14:036012. [PMID: 30870830 DOI: 10.1088/1748-3190/ab0fbe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this paper, we present a numerical model capable of solving the fluid-structure interaction problems involved in the dynamics of skeleton-reinforced fish fins. In this model, the fluid dynamics is simulated by solving the Navier-Stokes equations using a finite-volume method based on an overset, multi-block structured grid system. The bony rays embedded in the fin are modeled as nonlinear Euler-Bernoulli beams. To demonstrate the capability of this model, we numerically investigate the effect of various ray stiffness distributions on the deformation and propulsion performance of a 3D caudal fin. Our numerical results show that with specific ray stiffness distributions, certain caudal fin deformation patterns observed in real fish (e.g. the cupping deformation) can be reproduced through passive structural deformations. Among the four different stiffness distributions (uniform, cupping, W-shape and heterocercal) considered here, we find that the cupping distribution requires the least power expenditure. The uniform distribution, on the other hand, performs the best in terms of thrust generation and efficiency. The uniform stiffness distribution, per se, also leads to 'cupping' deformation patterns with relatively smaller phase differences between various rays. The present model paves the way for future work on dynamics of skeleton-reinforced membranes.
Collapse
Affiliation(s)
- Guangyu Shi
- Department of Naval Architecture, Ocean and Marine Engineering, University of Strathclyde, Glasgow, G4 0LZ, Scotland, United Kingdom
| | | | | | | |
Collapse
|