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One Step and In Situ Synthesis of Edible Lubricant-infused Surface Using All-in-one Solution

Daheng Wang, Jinxia Huang, Zhiguang Guo

Journal of Bionic Engineering. 2023 (5): 1879-1890. DOI: 10.1007/s42235-023-00379-1

摘要 ( 187 )

Edible Lubricant-Infused Surface (ELIS) was fabricated through antisolvent method by adding ethyl oleate (lubricant/antisolvent), ethanol (solvent) and shellac (solute/base layer of ELIS) into an all-in-one solution to in-situ prepare ELIS through single step of solvent evaporation. The ELIS comprising sub-micro- to micro-scaled shellac particles shows water and food liquid slippery, transparency, stability against abrasion and lubricant retaining ability against sheer force. Using all edible material to fabricated ELIS is a more efficient route for application when compared with other Lubricant-Infused Surface (LIS). Traditional fabrication for LIS included steps such as: base layer fabrication, lubricant infusion, excess lubricant removal, UV light treatment and chemical etching. The method proposed in this article could further simplify the preparation to an all-in-one solution and simplify the synthesis process to only 60-degree heating. Furthermore, Shellac ELIS coating could withstand abrasion and hold performance when compared with other ELIS coatings.

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A Super-robust Armoured Superhydrophobic Surface with Excellent Anti-icing Ability

Peng Wang, Hui Zhao, Boyuan Zheng, Ximei Guan, Bin Sun, Yongli Liao, Ying Yue, Wei Duan & Haimin Ding

Journal of Bionic Engineering. 2023 (5): 1891-1904. DOI: 10.1007/s42235-023-00381-7

摘要 ( 112 )

It has been proved that the construction of interconnected armour on superhydrophobic surface could significantly enhance the mechanical robustness. Here, a new kind of armour with frame/protrusion hybrid structure was achieved by nanosecond laser technology. Then, this armoured superhydrophobic surface demonstrated excellent durability, which could withstand linear abrasion (~?3 N press) 800 cycles, water jet test (1.0 MPa pressure) 40 times and 100 °C treatment 18 days. Particularly, the armoured superhydrophobic sample shows outstanding anti-icing ability, which can speed up the supercooled water dropping (no adhesion within 2 h), increase the freezing delay time by?~?3 times and maintain low adhesion force (less than 35 kPa) after 30 icing/de-icing cycles. Further finite element analysis and theoretical modeling proved that the developed frame/protuberance hybrid structure could effectively enhance the durability. The relatively low surface accuracy in this study can significantly reduce processing cost, which provides a bright future for the practical application of armour superhydrophobic materials

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Insight into the Lubrication Performance of Biomimetic Porous Structure Material for Water-lubricated Bearings

Xuefei Li, Zhiwei Guo, Qiren Huang, Chengqing Yuan

Journal of Bionic Engineering. 2023 (5): 1905-1916. DOI: 10.1007/s42235-023-00375-5

摘要 ( 140 )

Water-lubricated bearings have great advantages in the application of ship tail bearings due to the characteristics of green, pollution-free, and sustainable. However, the poor wettability of water-lubricated materials, as well as the low viscosity and poor load-carrying capacity of water, resulting in poor lubricating film integrity and short material service life under low-speed, heavy-load, start-stop conditions, which limits its application. To study the relationship between wettability and lubrication state and improve the lubrication performance of Si3N4 under water lubrication conditions, the characteristic parameters that determine the hydrophilicity of Sphagnum were detected and extracted, and the bionic Si3N4 model was established using Material Studio. Then, the molecular dynamic behavior and tribological properties of different Si3N4 models were simulated and analyzed. Pore structure affects the spreading and storage of water on the material surface and changes the wettability of the material. Under the condition of water lubrication, better wettability and water storage promote the formation of water film, effectively improve the lubrication state of the material, and improve its bearing performance

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Mechanical Characteristics Analysis of 3D-printing Novel Chiral Honeycomb Array Structures Based on Functional Principle and Constitutive Relationship

Ruiyao Liu, Guofeng Yao, Zezhou Xu, Xue Guo, Jianyong Li, Zhenglei Yu, Ping Liang, Zhihui Zhang, Chunyang Han

Journal of Bionic Engineering. 2023 (5): 1917-1929. DOI: 10.1007/s42235-023-00364-8

摘要 ( 128 )

Four novel chiral honeycomb structures inspired by the biological arrangement shape are designed. The functional principle is raised to solve the large deformation of bio-inspired structures and the structural constitutive model is proposed to explain the quasi-static mechanical properties of chiral honeycomb array structures and honeycomb structures. Simulation and experiment results verify the accuracy of theoretical analysis results and the errors are all within 15%. In structural mechanical properties, Equidimensional Chiral Honeycomb Array Structure (ECHS) has excellent mechanical properties. Among ECHS, Small-sized Column Chiral Honeycomb Array Structure (SCHCS) has the best properties. The bearing capacity, specific energy absorption, and specific strength of SCHCS are more than twice as much as the others in this paper. The chiral honeycomb array structure has the best mechanical properties at a certain size. In the structural design, the optimal size model should be obtained first in combination with the optimization algorithm for the protection design.

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Mechanistic Analysis and Bio-inspired Applications for a Bidirectional Stiffness of a Water Snail Operculum

Ke Xu, Xiaoming Xu, Qi Yang, Jianing Wu, Zhigang Wu, Jinzhao Yang

Journal of Bionic Engineering. 2023 (5): 1930-1941. DOI: 10.1007/s42235-023-00384-4

摘要 ( 86 )

The water snail Pomacea canaliculata retracts the discoidal and multi-layered operculum to protect the soft body from being attacked by predators, and releases it when threats lifted. However, the duration of the operculum retraction is usually less than that of the operculum protraction. In this paper, we elucidate the biological compliant mechanism of the operculum. By using confocal laser scanning microscopy, we find that the operculum has compliant sandwiched layers between hard layers. The layered structure results in a compliant mechanism with a bidirectional stiffness for the locking and unlocking processes of the operculum. A mathematical model is derived to rationalize the bidirectional stiffness mechanism of the operculum. In addition, we carry out the experiments on the locking and unlocking processes. The experimental results show that the locking tension is about two-fifths of the unlocking tension of the operculum. Moreover, based on the mechanical properties of the operculum with the layered structure, we designed an operculum-inspired structure, which may have a variety of potential applications in combined driving patterns

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Study of Impact Resistance Based on Porcupine Quills Bionic Thin-walled Structure

Tianshu Huang, Zhengyu Mao, Lijun Chang, Xingyuan Huang, Zhihua Cai

Journal of Bionic Engineering. 2023 (5): 1942-1955. DOI: 10.1007/s42235-023-00380-8

摘要 ( 130 )

Using an electron microscope to observe the microstructure of a porcupine quills cross-section and a bionic method, a new bionic structure was proposed. The performance of the structure in terms of energy absorption, maximum impact force withstood, and impact force efficiency was evaluated using Ansys finite element simulation software to simulate the structure's impact. To examine the impact of ribs on the structural performance of the bionic porcupine quills, a control structure was developed. According to the results of the finite element simulation, the presence of ribs in the Bionic porcupine quills structure can transfer stress uniformly to the overall structure and share stress for some of the rupture-prone regions. Ribs reduce stress concentration in specific areas and increase the impact force efficiency of the structure. The SEA and IFE values of bionic porcupine quills were 30.01 kJ/kg and 84.22%, respectively. The structure is then optimized for parameter design in order to find the optimal structure by response surface in order to improve the structure's SEA and decrease its MIF. In order to evaluate the precision of the response surface, the optimal structure predicted is validated using finite element simulation

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Nature-inspired Polysaccharide-based Aerogel for Oil–water Separation

Ye Fu, hulun Ai, Zhiguang Guo, Weimin Liu

Journal of Bionic Engineering. 2023 (5): 1956-1966. DOI: 10.1007/s42235-023-00370-w

摘要 ( 94 )

Oily wastewater pollution is an urgent problem to be solved. Complicated preparation process, toxic hydrophobic modifiers and poor mechanical properties limit the application of polysaccharide-based aerogel in oil–water separation. Inspired by the Strider’s Leg structure in nature, an eco-friendly and reusable polysaccharide-based composite aerogel was prepared by hydrophobic modification with zein for efficient oil–water separation. The introduction of hydrophobic zein into aerogel by simple immersion method without the use of toxic modifiers can build micro/nanostructures similar to the villi on a water strider’s leg to increase the surface roughness and the hydrophobicity. And three degradable, non-toxic and economical polysaccharides including chitosan, carboxylated cellulose nanofibers and starch were used to construct aerogel skeleton, endowing aerogel with porous structures and good mechanical properties. The resulting composite aerogel (ZOMA) showed low density (0.11 g/cm3), good oil absorption capacity (9 g/g), high flux oil–water separation (5595 L m?2 h?1) and excellent oil–water separation performance (99.8%). And ZOMA still had good tensile strength and elasticity after 50 compression cycles. After 10 cycles of absorption and desorption, ZOMA aerogel remained still more than 90% of its initial absorption capacity. This study provides new insight for the design of environmentally friendly and efficient adsorbents for oil–water separation.

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Laser Surface Texturing of Co–Cr–Mo Alloy for Biomedical Applications: A Case Study for the Effects of Process Parameters on Surface Properties

Şefika Kasman, İbrahim Can Uçar, Sertan Ozan

Journal of Bionic Engineering. 2023 (5): 1967-1984. DOI: 10.1007/s42235-023-00372-8

摘要 ( 88 )

This study presents a comprehensive approach to applying texturing processes created by engraving on the surface of CoCr28Mo alloy workpieces using a 20 W pulsed nanosecond fiber laser. The hatch strategy and distance, frequency, and scan speed were control parameters for texturing applications. The effectiveness of the parameters in terms of roughness and contact angle of the texturized surface was investigated. Surface roughness and contact angle were analyzed using variance analysis to identify each variable's influence. It has been determined that the roughness of the texture defined by the hatch strategy plays a decisive role in the wettability behavior of the surface; however, the scan speed, frequency, and hatch distance which are among the laser surface texturing conditions are influential in the roughness and contact angle. Increasing scan speed and hatch distance while decreasing frequency resulted in smoother surfaces, increasing the contact angle. Textures having rough surfaces produced with different processing conditions exhibit a super hydrophilic behavior. The contact angle is most sensitive to the hatch distance; however, the frequency has the least influence on the contact angle. The most and least efficient surface roughness parameters are revealed to be scan speed and hatch distance, respectively.

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Biomimetic Preparation of Alumina Hierarchical Papillary Microrough Structure for Hydrophobic Improvement and Its Abrasion Resistance Finite Element Analysis

Meng Liu, Junxin Lu, Zhihui Cao, Kang Yang, Tingting Mi, Jianlin Li, Jianbao Li, Hui Yu

Journal of Bionic Engineering. 2023 (5): 1985-1995. DOI: 10.1007/s42235-023-00383-5

摘要 ( 92 )

The surface of lotus leaves has a hierarchical micro–nano-rough structure. We determined that the papillary structure also possesses hierarchical features on the microscale. We used alumina particles as rough structure building units to construct a Hierarchical Papillary microrough Structure (HPS) on a ceramic surface. The effects of the spatial distribution of HPS on the abrasion resistance and mechanical stability of hydrophobic coatings were investigated. Furthermore, for each HPS, the falling sand abrasion process was analyzed using finite element fluid mechanics analysis. A denser or more two-dimensional HPS implied that more area was impacted by the falling sand and that the abrasion amount and rate were higher. This is contrary to the common belief that when there are more wear-resistant substances on the surface, the abrasion resistance is better; thus, abrasion resistance does not necessarily depend entirely on the concentration of wear-resistant substances on the surface, but it is also influenced by the abrasion mode and the spatial distribution structure of the wear-resistant substances. The 3D stacked HPS (3D-HPS) with excellent abrasion resistance and rich pore structure considerably enhanced the mechanical stability of the hydrophobic coatings. These findings provide novel insights and a theoretical basis for designing spatial structures on high abrasion-resistant superhydrophobic ceramic surfaces.

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Biologically Inspired Girder Structure for the Synchrotron Radiation Facility PETRA IV

Simone Andresen, Norbert Meyners, Daniel Thoden, Markus Körfer, Christian Hamm

Journal of Bionic Engineering. 2023 (5): 1996-2017. DOI: 10.1007/s42235-023-00373-7

摘要 ( 86 )

Lightweight structures are widely used across different industry sectors. However, they get easily excited by external influences, such as vibrations. Undesired high vibration amplitudes can be avoided by shifting the structural eigenfrequencies, which can be achieved adapting the structural design considering optimisation procedures and structures primarily inspired by diatoms. This procedures has been applied to the development process of a girder structure installed in a synchrotron radiation facility to support heavy magnets and other components. The objective was to design a 2.9 m long girder structure with high eigenfrequencies, a high stiffness and a low mass. Based on a topology optimisation result, a parametric beam–shell model including biologically inspired structures (e.g., Voronoi combs, ribs, and soft and organic-looking transitions) was built up. The subsequent cross-sectional optimisation using evolutionary strategic optimisation revealed an optimum girder structure, which was successfully manufactured using the casting technology. Eigenfrequency measurements validated the numerical models. Future changes in the specifications can be implemented in the bio-inspired development process to obtain adapted girder structures.

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Optimal Design and Mechanical Simulation of Rubber bushing with Convex Hull Structure Based on Bionics

Ce Liang, Min Li, Jicai Liang, Shaoqiang Wang, Qigang Han, Yi Li

Journal of Bionic Engineering. 2023 (5): 2018-2029. DOI: 10.1007/s42235-023-00388-0

摘要 ( 78 )

Inspired by the safe landing of cats falling from high altitudes, a bionic flexible rubber bushing structure is proposed and its motion characteristics are systematically studied to explore its potential application in the suppression of vibration. The convex hull structure on the bushing surface is abstracted from the cat’s claw pad, and the hyper-viscoelastic model is selected as the constitutive model of the rubber material. In addition, the design with the best vibration damping effect is finally obtained by reasonably adjusting the amount of radial compression and distribution of bionic structures. Finally, under the same conditions, the test results of the dynamic characteristics of the bushing verify the accuracy of the simulation results. Research results show that the convex hull bionic structure designed in this paper can effectively change the motion characteristics of the rubber bushing under various working conditions, which provides new inspiration or potential possibility for the design of rubber bushing in the future.

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A Soft Robotic Fish Actuated by Artificial Muscle Modules (SoRoFAAM-1)

Moise Raphael Tsimbo Fokou, Qirong Xia, Hu Jin, Min Xu, Erbao Dong

Journal of Bionic Engineering. 2023 (5): 2030-2043. DOI: 10.1007/s42235-023-00390-6

摘要 ( 115 )

In this paper, we present the design, fabrication, locomotion and bionic analysis of a Soft Robotic Fish Actuated by Artificial Muscle (SoRoFAAM). As a carangiform swimmer, the most important part of SoRoFAAM-1, on the motion point of view, is its tail designed around a bidirectional flexible bending actuator by layered bonding technology. This actuator is made of two artificial muscle modules based on Shape Memory Alloy (SMA) wires. Each artificial muscle module has four independent SMA-wire channels and is therefore capable of producing four different actuations. This design allows us to implement an adaptive regulated control strategy based on resistance feedback of the SMA wires to prevent them from overheating. To improve the actuation frequency to 2 Hz and the heat-dissipation ratio by 60%, we developed a round-robin heating strategy. Furthermore, the thermomechanical model of actuator is built, and the thermal transformation is analysed. The relationships between the actuation parameters and SoRoFAAM-1’s kinematic parameters are analysed. The versatility of the actuator endows SoRoFAAM-1 with cruise straight and turning abilities. Moreover, SoRoFAAM-1 has a good bionic fidelity; in particular, a maneuverability of 0.15, a head swing factor of 0.38 and a Strouhal number of 0.61.

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A Bioinspired Robot Growing like Plant Roots

Giovanni Bianchi, Aldo Agoni, Simone Cinquemani

Journal of Bionic Engineering. 2023 (5): 2044-2058. DOI: 10.1007/s42235-023-00369-3

摘要 ( 107 )

Plants are usually considered static organisms, but they can perform a wide range of movements that can be a source of inspiration for robots. The roots’ growing motion is the most noteworthy since they are excellent diggers that can move in unstructured environments and navigate past barriers. Furthermore, root growth has a high energy efficiency since it penetrates the soil at its tip, adding new material without displacing the already grown portion, minimizing the energy dissipation due to friction and lowering the inertia. A robot inspired by the growth of roots could be used in search and rescue or environmental monitoring. The design of a soft robot inspired by root growth is presented in this article. The robot body consists of a cylindrical plastic membrane folded inside itself. The robot body is inflated, and its tip is everted, expanding its length as air is blown from the base. Velcro straps are placed on the membrane’s exterior surface to keep it folded. The head is positioned inside the tip, which houses the mechanism that controls the growth direction. It consists of housing for two balloons that are selectively inflated, and their expansion applies pressure on the exterior surface, opening the Velcro straps and determining the growth direction. The robot was constructed, and a kinematic model of its motion in the plane was created and compared with experimental data. The error in predicting the turning angle is only 5%, and the resulting predicted position differs on average by 55 mm on a total length of 850 mm.

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Intrinsic Kinematics of the Tibiotalar and Subtalar Joints during Human Walking based on Dynamic Biplanar Fluoroscopy

Shengli Wang, Zhihui Qian, Xiangyu Liu, Guangsheng Song, Kunyang Wang, Jianan Wu, Jing Liu, Lei Ren, Luquan Ren

Journal of Bionic Engineering. 2023 (5): 2059-2068. DOI: 10.1007/s42235-023-00368-4

摘要 ( 80 )

Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex (AJC) is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders, as well as an essential guide to the design of ankle–foot assistant devices. However, detailed analysis of the continuous 3D motion of the tibiotalar and subtalar joints during normal walking throughout the stance phase is still considered to be lacking. In this study, dynamic radiographs of the hindfoot were acquired from eight subjects during normal walking. Natural motions with six Degrees of Freedom (DOF) and the coupled patterns of the two joints were analyzed. It was found that the movements of the two joints were mostly in opposite directions (including rotation and translation), mainly in the early and late stages. There were significant differences in the Range of Motion (ROM) in Dorsiflexion/Plantarflexion (D/P), Inversion/Eversion (In/Ev), and Anterior–Posterior (AP) and Medial–Lateral (ML) translation of the tibiotalar and subtalar joints (p?<?0.05). Plantarflexion of the tibiotalar joint was coupled with eversion and posterior translation of the subtalar joint during the impact phase (R2?=?0.87 and 0.86, respectively), and plantarflexion of the tibiotalar joint was coupled with inversion and anterior translation of the subtalar joint during the push-off phase (R2?=?0.93 and 0.75, respectively). This coordinated coupled motion of the two joints may be a manifestation of the AJC to move flexibly while bearing weight and still have stability.

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Task-space Whole-body Control with Variable Contact Force Control for Position-controlled Humanoid Adaptation to Unknown Disturbance

Zelin Huang, Chencheng Dong, Zhangguo Yu, Xuechao Chen, Fei Meng, Qiang Huang

Journal of Bionic Engineering. 2023 (5): 2069-2087. DOI: 10.1007/s42235-023-00378-2

摘要 ( 90 )

Whole-body control is beneficial for improving the disturbance adaptation of humanoid robots, since it can simultaneously optimize desired joint torque, joint acceleration, and contact force while considering whole-body dynamics and other physical limits. However, the lack of torque feedback information prevents the position-controlled humanoids from utilizing whole-body control directly, because it enhances the difficulty of guaranteeing desired contact force which is important for maintaining stability. In this paper, a whole-body control that integrates task-space inverse dynamics and variable contact force control is proposed for position-controlled humanoids to enhance the robot’s adaptability toward the unknown disturbance. The task-space inverse dynamics generates the desired joint acceleration and contact force with the consideration of whole-body dynamics and other limits to track the references. The variable contact force control modifies references related to Center of Mass (CoM) and end effectors to ensure reasonable contact force tracking performance, thereby assuring good tracking performance of CoM and momentum to maintain robot stability. Simulations and experiments of balancing and walking under unknown disturbance have been successfully conducted on a position-controlled humanoid robot, BHR-7P3, with the proposed method.

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Research on Bionic Jumping and Soft Landing of Single Leg System in Quadruped Robot

Jinzhu Zhang, Miao Li, Jiandong Cao, Yuhan Dou, Xiaoyan Xiong

Journal of Bionic Engineering. 2023 (5): 2088-2107. DOI: 10.1007/s42235-023-00360-y

摘要 ( 134 )

This paper proposed a novel multi-motion wheel-leg-separated quadruped robot that can adapt to both the structured and unstructured grounds. The models of the positive/inverse position, velocity, acceleration, and workspace of the single leg mechanism in the quadruped robot were established. A single leg complex dynamic model of the quadruped robot is derived, considering the mass and inertial force of all the components in the mechanical leg. Combined with the human jumping law in situ, the jumping trajectory of the single leg was planned. To reduce landing impact, a soft landing strategy based on motion planning was proposed by simulating human knee bending and buffering action. The change law of the kinetic energy and momentum of all the links in the single leg mechanism during the jump process was studied, and the influencing factors of jump height were analyzed to realize the height control of the jump. Single leg jumping dynamics model was established, and a dynamic control strategy for trajectory tracking with foot force compensation was proposed. In Adams and MATLAB/Simulink software, the jump simulation of single leg mechanism was carried out. The prototype of quadruped robot was developed, and the jumping experiment of the single leg mechanism was tested. The robot's single leg bionic jumping and soft landing control are realized.

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A Unified Trajectory Optimization Approach for Long-Term and Reactive Motion Planning of Legged Locomotion

Yapeng Shi, Bin Yu, Kaixian Ba, Mantian Li

Journal of Bionic Engineering. 2023 (5): 2108-2122. DOI: 10.1007/s42235-023-00362-w

摘要 ( 104 )

This paper proposes a unified trajectory optimization approach that simultaneously optimizes the trajectory of the center of mass and footholds for legged locomotion. Based on a generic point-mass model, the approach is formulated as a nonlinear optimization problem, incorporating constraints such as robot kinematics, dynamics, ground reaction forces, obstacles, and target location. The unified optimization approach can be applied to both long-term motion planning and the reactive online planning through the use of model predictive control, and it incorporates vector field guidance to converge to the long-term planned motion. The effectiveness of the approach is demonstrated through simulations and physical experiments, showing its ability to generate a variety of walking and jumping gaits, as well as transitions between them, and to perform reactive walking in obstructed environments.

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Design and Grasping Force Modeling for a Soft Robotic Gripper with Multi‑stem Twining

Yu Shan, Yanzhi Zhao, Hongnian Yu, Changlei Pei, Zhaopeng Jin, Yue Sun

Journal of Bionic Engineering. 2023 (5): 2123-2134. DOI: 10.1007/s42235-023-00371-9

摘要 ( 84 )

To improve the grasping power of soft robots, inspired by the scene of intertwined and interdependent vine branches safely clinging to habitats in a violent storm and the phenomenon of large grasping force after being entangled by aquatic plants, this paper proposes a soft robotic gripper with multi-stem twining. The proposed robotic gripper can realize a larger contact area of surrounding or containing object and more layers of a twining object than the current twining gripping methods. It not only retains the adaptive advantages of twining grasping but also improves the grasping force. First, based on the mechanical characteristics of the multi-stem twining of the gripper, the twining grasping model is developed. Then, the force on the fiber is deduced by using the twining theory, and the axial force of the gripper is analyzed based on the equivalent model of the rubber ring. Finally, the torsion experiments of fibers and the grasping experiments of the gripper are designed and conducted. The torsion experiment of fibers verifies the influence of a different number of fiber ropes and fiber torque on the grasping force, and the grasping experiment reflects the large load of the gripper and the high adaptability and practicability under different tasks.

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Comparing Online Performance of EMG Pattern Recognition with and Without Joint Movements

Lizhi Pa, Kai Liu, Jianmin Li

Journal of Bionic Engineering. 2023 (5): 2135-2146. DOI: 10.1007/s42235-023-00376-4

摘要 ( 65 )

Our previous study suggested that the subcutaneous muscle displacement caused by joint movements might alter muscle activation patterns and thus affect the classification performance. To further analyze the effect of joint movements on the online performance of Electromyography (EMG) Pattern Recognition (PR), this study assessed online classification performance with and without joint movements. EMG signals were recorded from the dominant forearm of 10 able-bodied subjects under two motion scenarios: Hand and Wrist Joints Unconstrained (HAWJU) and Constrained (HAWJC). Sixth-order autoregressive coefficients and four time-domain features were extracted from EMG signals. Linear Discriminant Analysis (LDA) models were trained to perform an online performance evaluation of the limb motions. The experimental results showed that the four online performance metrics: Motion Selection Time (MST), Motion Completion Time (MCT), Motion Completion Rate (MCR), and Online Classification Accuracy (ONCA) were 0.35 s, 1.44 s, 97.40%, and 82.61% for HAWJU and 0.37 s, 1.47 s, 89.70%, and 73.57% for HAWJC, respectively. The outcomes of this study indicated that subcutaneous muscle displacement due to joint movements has a positive effect on online classification performance. The absence of joint movements may be a physiological factor contributing to the poor online performance of the EMG-PR of transradial amputees. This study can provide a new perspective for improving the online performance of EMG-PR for transradial amputees.

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Performance Analysis and Flexible Control of a Novel Ball Double‑screw Hydraulic Robot Knee Joint

Jie Shao, Yongming Bian, Meng Yang , Guangjun Liu

Journal of Bionic Engineering. 2023 (5): 2147-2163. DOI: 10.1007/s42235-023-00374-6

摘要 ( 132 )

Focusing on the ball double-screw hydraulic knee joint as the research object, this paper analyzes the load driving performance of the hydraulic knee joint. Taking the posture data of the human body such as walking, squatting and landing buffer as initial learning objects, motion features are extracted. By simplifying the trajectories of different motion actions into key feature control points and flexible trajectory fitting, the trajectory of joint actions is optimized. This method can realize the adaptability of the hydraulic robot knee joint in different movements, and take the flexible action as the optimization goal under the condition of ensuring the movement performance, so as to reduce the damage to the knee joint caused by the foot impact in motion. The simulation model was built by Adams and Matlab to complete the performance analysis and motion optimization experiment of the knee joint. The simulation results show that the foot impact force of the experimental model decreases gradually through optimization. Finally, the method is applied to the hydraulic joint experimental prototype to prove its load capacity and flexible motion control performance.

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Minimum‑Time and Minimum‑Jerk Gait Planning in Joint Space for Assistive Lower Limb Exoskeleton

Habib Mohamad, Sadjaad Ozgoli , Fadi Motawej

Journal of Bionic Engineering. 2023 (5): 2164-2178. DOI: 10.1007/s42235-023-00363-9

摘要 ( 86 )

Assistive lower limb exoskeleton robot has been developed to help paraplegic patients walk again. A gait planning method of this robot must be able to plan a gait based on gait parameters, which can be changed during the stride according to human intention or walking conditions. The gait is usually planned in cartesian space, which has shortcomings such as singularities that may occur in inverse kinematics equations, and the angular velocity of the joints cannot be entered into the calculations. Therefore, it is vital to have a gait planning method in the joint space. In this paper, a minimum-time and minimum-jerk planner is proposed for the robot joints. To do so, a third-order system is defined, and the cost function is introduced to minimize the jerk of the joints throughout the stride. The minimum time required is calculated to keep the angular velocity trajectory within the range specified by the motor’s maximum speed. Boundary conditions of the joints are determined to secure backward balance and fulfill gait parameters. Finally, the proposed gait planning method is tested by its implementation on the Exoped? exoskeleton.

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Study on the Vibration Reduction Characteristics of FWMAV Flexible Bionic Wings Mimicking the Hindwings of Trypoxylus dichotomus

Yongwei Yan, Fa Song, Nuo Xu, Haochen Zhu, Hongxu Xing, Shujun Zhang, Jiyu Sun

Journal of Bionic Engineering. 2023 (5): 2179-2193. DOI: 10.1007/s42235-023-00385-3

摘要 ( 93 )

Using the method of structural finite element topology optimization and analysis of the hindwings of Trypoxylus dichotomus, this work identified the main loading force transmission path and designed the initial structure of a bionic flexible wing. A structural design scheme of the vibration damping unit was proposed, and the structural mechanics and modal vibration characteristics were simulated and analyzed. 3D printing technology was used to manufacture the designed bionic wing skeleton, which was combined with two kinds of wing membrane materials. The Flapping Wing Micro-aerial Vehicle (FWMAV) transmission mechanism vibration characteristics were observed and analyzed by a high-speed digital camera. A triaxial force transducer was used to record the force vibration of the flexible bionic wing flapping in a wind tunnel. A wavelet processing method was used to process and analyze the force signal. The results showed that the force amplitude was more stable, the waveform roughness was the lowest, and the peak shaving phenomenon at the z-axis was the least obvious for the bionic flexible wing model that combined the topology-optimized bionic wing skeleton with a polyamide elastic membrane. This was determined to be the most suitable design scheme for the wings of FWMAVs.

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Bionic Vibration Isolator Inspired by Goat Hind Limb

Xiaojie Shi, Jin Xu, Tingkun Chen, Cong Qian, Weijun Tian

Journal of Bionic Engineering. 2023 (5): 2194-2208. DOI: 10.1007/s42235-023-00352-y

摘要 ( 107 )

The goat’s hind limbs play an important role in dampening vibrations caused by ground impact during movement. Inspired by the unique structure of their hind limbs, a novel bionic limb vibration isolator has been developed to suppress low-frequency vibrations. It consists of the base, the carrying platform, four bionic legs and so on. The bionic legs are made up of rods of varying lengths and springs in different directions to imitate the various shapes of bones such as the femur and patella of the hind limbs of goats and developed muscles such as the biceps and quadriceps. The bionic device was found to have excellent nonlinear stiffness through statics analysis, and could be flexibly adjusted to the work range and load capacity. The bionic vibration isolator offers lower natural frequencies (2.3 Hz), better vibration isolation effect and a wider vibration isolation band than conventional linear vibration isolator. The bionic device can effectively suppress vibrations above 3.2 Hz and reduce the amplitude of random vibrations to more than 90%. In addition, compared to similar bionic vibration isolation devices, the bionic isolator achieves excellent load-bearing capacity in a smaller size, which facilitates its application in practical production.

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Bionic Volute Tongue Optimization Design of Multi‑blade Centrifugal Fan Inspired by the Wave Leading‑edge of Humpback Whale Flippers

Yang Liu, Qi Yuan, Ziqian Xu, Liming Wu, Xiaomin Liu

Journal of Bionic Engineering. 2023 (5): 2209-2227. DOI: 10.1007/s42235-023-00354-w

摘要 ( 111 )

The volute tongue can split the gas in the multi-blade centrifugal fan to make the gas flow to the volute outlet as much as possible. However, the unsteady axial deflection of the gas in the impeller results in different air flow angles at the outlet of the impeller at different blade heights. This seriously affects the flow near the volute tongue. The wave leading-edge structure of humpback whale flippers has a very high flow control effect under complex flow conditions. Therefore, the wave leading-edge structure is studied in this paper and applied to the optimization design of multi-blade centrifugal fan volute tongue. First, based on the wave leading-edge structure of humpback whale flippers, three-dimensional wave leading-edge airfoils with different wave direction angles are established to judge the adaptability of the new wave leading-edge structure under different attack angles. Then, aiming at the internal flow field and noise characteristics of multi-blade centrifugal fan, a bionic volute tongue optimization design method is proposed, and studied its influence on the internal flow field and noise characteristics of the fan. The results show that when the wave direction angle is 45°, the wave leading-edge structure can effectively suppress the generation of the leading-edge separation vortex and the shedding of the wake vortex, which is also helpful to reduce the noise. The bionic volute tongue with the wave leading-edge structure can adapt to the situation that the impeller outlet air flow angle is small. At the maximum volume flow rate operating point, the static pressure recovery coefficient of the bionic volute tongue fan is increased by about 5% compared to the original fan, the air volume is increased by 5.16%, and the noise is reduced by 0.6 dB.

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Stratum Griseum Periventriculare‑mediated Fear Emotion Regulates Motor Behavior in Pigeons

Wenbo Xu, Long Yang, Zishi Wang, Lifang Yang, Han Cheng, Shixin Zhu, Zhigang Shang, Zhenlong Wang

Journal of Bionic Engineering. 2023 (5): 2228-2239. DOI: 10.1007/s42235-023-00382-6

摘要 ( 88 )

A pigeon robot is an ideal experimental animal for research in flying animal robots. The majority of current research publications have entailed electrical stimulation of the motor nuclei to regulate movement forcibly, and although a “virtual fear” behavior model has been proposed, the structure, location, and function of the nuclei that generate fear emotions remain obscure. Previous studies have shown that the Stratum Griseum Periventriculare (SGP) of pigeons is homologous to the mammalian periaqueductal gray (PAG), which plays an essential role in mammalian fear. To reveal the role of fear mediated by the SGP in behavioral regulation, we evaluated the structure and location of the SGP by histologic identification combined with magnetic resonance imaging, and analyzed the behavior of the SGP by electrical stimulation. Finally, the function of the SGP was verified with escape testing and homing experiments in an open field. Our results showed that the SGP is located in the pigeon midbrain and divided into two subregions, the dorsal part of the stratum griseum periventriculare (SGPd) and the ventral part of the stratum griseum periventriculare (SGPv) (the ranges were AP1.5–4.75 mm, ML1.75–6.75 mm, and DV2.2–7.1 mm), and that wired and wireless electrical stimulation freezing was the dominant behavior. In the escape test, SGP electrical stimulation caused the pigeons to flee to a safe place, while in the open-field homing test, electrical stimulation of the SGP induced evasive behavior in pigeons away from their original homing route. These results confirm that the SGP plays a crucial role in fear, and that electrical stimulation of this nucleus induces corresponding fear behaviors.

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Renal Pathology Images Segmentation Based on Improved Cuckoo Search with Difusion Mechanism and Adaptive Beta‑Hill Climbing

Jiaochen Chen, Zhennao Cai, Huiling Chen, Xiaowei Chen, José Escorcia-Gutierrez, Romany F. Mansour, Mahmoud Ragab

Journal of Bionic Engineering. 2023 (5): 2240-2275. DOI: 10.1007/s42235-023-00365-7

摘要 ( 78 )

Lupus Nephritis (LN) is a significant risk factor for morbidity and mortality in systemic lupus erythematosus, and nephropathology is still the gold standard for diagnosing LN. To assist pathologists in evaluating histopathological images of LN, a 2D Rényi entropy multi-threshold image segmentation method is proposed in this research to apply to LN images. This method is based on an improved Cuckoo Search (CS) algorithm that introduces a Diffusion Mechanism (DM) and an Adaptive β-Hill Climbing (AβHC) strategy called the DMCS algorithm. The DMCS algorithm is tested on 30 benchmark functions of the IEEE CEC2017 dataset. In addition, the DMCS-based multi-threshold image segmentation method is also used to segment renal pathological images. Experimental results show that adding these two strategies improves the DMCS algorithm's ability to find the optimal solution. According to the three image quality evaluation metrics: PSNR, FSIM, and SSIM, the proposed image segmentation method performs well in image segmentation experiments. Our research shows that the DMCS algorithm is a helpful image segmentation method for renal pathological images.

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An Efcient Multilevel Threshold Image Segmentation Method for COVID‑19 Imaging Using Q‑Learning Based Golden Jackal Optimization

Zihao Wang, Yuanbin Mo, Mingyue Cui

Journal of Bionic Engineering. 2023 (5): 2276-2316. DOI: 10.1007/s42235-023-00391-5

摘要 ( 81 )

From the end of 2019 until now, the Coronavirus Disease 2019 (COVID-19) has been rampaging around the world, posing a great threat to people's lives and health, as well as a serious impact on economic development. Considering the severely infectious nature of COVID-19, the diagnosis of COVID-19 has become crucial. Identification through the use of Computed Tomography (CT) images is an efficient and quick means. Therefore, scientific researchers have proposed numerous segmentation methods to improve the diagnosis of CT images. In this paper, we propose a reinforcement learning-based golden jackal optimization algorithm, which is named QLGJO, to segment CT images in furtherance of the diagnosis of COVID-19. Reinforcement learning is combined for the first time with meta-heuristics in segmentation problem. This strategy can effectively overcome the disadvantage that the original algorithm tends to fall into local optimum. In addition, one hybrid model and three different mutation strategies were applied to the update part of the algorithm in order to enrich the diversity of the population. Two experiments were carried out to test the performance of the proposed algorithm. First, compare QLGJO with other advanced meta-heuristics using the IEEE CEC2022 benchmark functions. Secondly, QLGJO was experimentally evaluated on CT images of COVID-19 using the Otsu method and compared with several well-known meta-heuristics. It is shown that QLGJO is very competitive in benchmark function and image segmentation experiments compared with other advanced meta-heuristics. Furthermore, the source code of the QLGJO is publicly available at https://github.com/Vang-z/QLGJO.

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Performance Analysis of 5 G Wireless Hybrid Precoding Using Evolutionary Algorithms

Madhusmita Sahoo , Harish Kumar Sahoo

Journal of Bionic Engineering. 2023 (5): 2317-2330. DOI: 10.1007/s42235-023-00377-3

摘要 ( 79 )

Emerging 5G communication solutions utilize the millimeter wave (mmWave) band to alleviate the spectrum deficit. In the mmWave range, Multiple Input Multiple Output (MIMO) technologies support a large number of simultaneous users. In mmWave MIMO wireless systems, hybrid analog/digital precoding topologies provide a reduced complexity substitute for digital precoding. Bit Error Rate (BER) and Spectral efficiency performances can be improved by hybrid Minimum Mean Square Error (MMSE) precoding, but the computation involves matrix inversion process. The number of antennas at the broadcasting and receiving ends is quite large for mm-wave MIMO systems, thus computing the inverse of a matrix of such high dimension may not be practically feasible. Due to the need for matrix inversion and known candidate matrices, the classic Orthogonal Matching Pursuit (OMP) approach will be more complicated. The novelty of research presented in this manuscript is to create a hybrid precoder for mmWave communication systems using metaheuristic algorithms that do not require matrix inversion processing. The metaheuristic approach has not employed much in the formulation of a precoder in wireless systems. Five distinct evolutionary algorithms, such as Harris–Hawks Optimization (HHO), Runge–Kutta Optimization (RUN), Slime Mould Algorithm (SMA), Hunger Game Search (HGS) Algorithm and Aquila Optimizer (AO) are considered to design optimal hybrid precoder for downlink transmission and their performances are tested under similar practical conditions. According to simulation studies, the RUN-based precoder performs better than the conventional algorithms and other nature-inspired algorithms based precoding in terms of spectral efficiency and BER.

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Discrete Improved Grey Wolf Optimizer for Community Detection

Mohammad H. Nadimi-Shahraki, Ebrahim Moeini, Shokooh Taghian, Seyedali Mirjalili

Journal of Bionic Engineering. 2023 (5): 2331-2358. DOI: 10.1007/s42235-023-00387-1

摘要 ( 76 )

Detecting communities in real and complex networks is a highly contested topic in network analysis. Although many metaheuristic-based algorithms for community detection have been proposed, they still cannot effectively fulfill large-scale and real-world networks. Thus, this paper presents a new discrete version of the Improved Grey Wolf Optimizer (I-GWO) algorithm named DI-GWOCD for effectively detecting communities of different networks. In the proposed DI-GWOCD algorithm, I-GWO is first armed using a local search strategy to discover and improve nodes placed in improper communities and increase its ability to search for a better solution. Then a novel Binary Distance Vector (BDV) is introduced to calculate the wolves’ distances and adapt I-GWO for solving the discrete community detection problem. The performance of the proposed DI-GWOCD was evaluated in terms of modularity, NMI, and the number of detected communities conducted by some well-known real-world network datasets. The experimental results were compared with the state-of-the-art algorithms and statistically analyzed using the Friedman and Wilcoxon tests. The comparison and the statistical analysis show that the proposed DI-GWOCD can detect the communities with higher quality than other comparative algorithms.

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A Global Best‑guided Firefy Algorithm for Engineering Problems

Mohsen Zare, Mojtaba Ghasemi, Amir Zahed, Keyvan Golalipour, Soleiman Kadkhoda Mohammadi, Seyedali Mirjalili, Laith Abualigah

Journal of Bionic Engineering. 2023 (5): 2359-2388. DOI: 10.1007/s42235-023-00386-2

摘要 ( 232 )

The Firefly Algorithm (FA) is a highly efficient population-based optimization technique developed by mimicking the flashing behavior of fireflies when mating. This article proposes a method based on Differential Evolution (DE)/current-to-best/1 for enhancing the FA's movement process. The proposed modification increases the global search ability and the convergence rates while maintaining a balance between exploration and exploitation by deploying the global best solution. However, employing the best solution can lead to premature algorithm convergence, but this study handles this issue using a loop adjacent to the algorithm's main loop. Additionally, the suggested algorithm’s sensitivity to the alpha parameter is reduced compared to the original FA. The GbFA surpasses both the original and five-version of enhanced FAs in finding the optimal solution to 30 CEC2014 real parameter benchmark problems with all selected alpha values. Additionally, the CEC 2017 benchmark functions and the eight engineering optimization challenges are also utilized to evaluate GbFA’s efficacy and robustness on real-world problems against several enhanced algorithms. In all cases, GbFA provides the optimal result compared to other methods. Note that the source code of the GbFA algorithm is publicly available at https://www.optim-app.com/projects/gbfa.

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A Novel Variant of Moth Flame Optimizer for Higher Dimensional Optimization Problems

Saroj Kumar Sahoo, Sushmita Sharma, Apu Kumar Saha

Journal of Bionic Engineering. 2023 (5): 2389-2415. DOI: 10.1007/s42235-023-00357-7

摘要 ( 100 )

Moth Flame Optimization (MFO) is a nature-inspired optimization algorithm, based on the principle of navigation technique of moth toward moon. Due to less parameter and easy implementation, MFO is used in various field to solve optimization problems. Further, for the complex higher dimensional problems, MFO is unable to make a good trade-off between global and local search. To overcome these drawbacks of MFO, in this work, an enhanced MFO, namely WF-MFO, is introduced to solve higher dimensional optimization problems. For a more optimal balance between global and local search, the original MFO’s exploration ability is improved by an exploration operator, namely, Weibull flight distribution. In addition, the local optimal solutions have been avoided and the convergence speed has been increased using a Fibonacci search process-based technique that improves the quality of the solutions found. Twenty-nine benchmark functions of varying complexity with 1000 and 2000 dimensions have been utilized to verify the projected WF-MFO. Numerous popular algorithms and MFO versions have been compared to the achieved results. In addition, the robustness of the proposed WF-MFO method has been evaluated using the Friedman rank test, the Wilcoxon rank test, and convergence analysis. Compared to other methods, the proposed WF-MFO algorithm provides higher quality solutions and converges more quickly, as shown by the experiments. Furthermore, the proposed WF-MFO has been used to the solution of two engineering design issues, with striking success. The improved performance of the proposed WF-MFO algorithm for addressing larger dimensional optimization problems is guaranteed by analyses of numerical data, statistical tests, and convergence performance.

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Dynamic Individual Selection and Crossover Boosted Forensic‑based Investigation Algorithm for Global Optimization and Feature Selection

Hanyu Hu, Weifeng Shan, Jun Chen, Lili Xing, Ali Asghar Heidari, Huiling Chen, Xinxin He, Maofa Wang

Journal of Bionic Engineering. 2023 (5): 2416-2442. DOI: 10.1007/s42235-023-00367-5

摘要 ( 80 )

The advent of Big Data has rendered Machine Learning tasks more intricate as they frequently involve higher-dimensional data. Feature Selection (FS) methods can abate the complexity of the data and enhance the accuracy, generalizability, and interpretability of models. Meta-heuristic algorithms are often utilized for FS tasks due to their low requirements and efficient performance. This paper introduces an augmented Forensic-Based Investigation algorithm (DCFBI) that incorporates a Dynamic Individual Selection (DIS) and crisscross (CC) mechanism to improve the pursuit phase of the FBI. Moreover, a binary version of DCFBI (BDCFBI) is applied to FS. Experiments conducted on IEEE CEC 2017 with other metaheuristics demonstrate that DCFBI surpasses them in search capability. The influence of different mechanisms on the original FBI is analyzed on benchmark functions, while its scalability is verified by comparing it with the original FBI on benchmarks with varied dimensions. The results show that BDCFBI can be more competitive than similar methods and acquire a subset of features with superior classification accuracy.

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The Application of Hybrid Krill Herd Artifcial Hummingbird Algorithm for Scientifc Workfow Scheduling in Fog Computing

Aveen Othman Abdalrahman, Daniel Pilevarzadeh, Shafi Ghafouri & Ali Ghaffari

Journal of Bionic Engineering. 2023 (5): 2443-2464. DOI: 10.1007/s42235-023-00389-z

摘要 ( 83 )

Fog Computing (FC) provides processing and storage resources at the edge of the Internet of Things (IoT). By doing so, FC can help reduce latency and improve reliability of IoT networks. The energy consumption of servers and computing resources is one of the factors that directly affect conservation costs in fog environments. Energy consumption can be reduced by efficacious scheduling methods so that tasks are offloaded on the best possible resources. To deal with this problem, a binary model based on the combination of the Krill Herd Algorithm (KHA) and the Artificial Hummingbird Algorithm (AHA) is introduced as Binary KHA- AHA (BAHA-KHA). KHA is used to improve AHA. Also, the BAHA-KHA local optimal problem for task scheduling in FC environments is solved using the dynamic voltage and frequency scaling (DVFS) method. The Heterogeneous Earliest Finish Time (HEFT) method is used to discover the order of task flow execution. The goal of the BAHA-KHA model is to minimize the number of resources, the communication between dependent tasks, and reduce energy consumption. In this paper, the FC environment is considered to address the workflow scheduling issue to reduce energy consumption and minimize makespan on fog resources. The results were tested on five different workflows (Montage, CyberShake, LIGO, SIPHT, and Epigenomics). The evaluations show that the BAHA-KHA model has the best performance in comparison with the AHA, KHA, PSO and GA algorithms. The BAHA-KHA model has reduced the makespan rate by about 18% and the energy consumption by about 24% in comparison with GA.

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The Bedbug Meta‑heuristic Algorithm to Solve Optimization Problems

Kouroush Rezvani, Ali Gaffari, Mohammad Reza Ebrahimi Dishabi

Journal of Bionic Engineering. 2023 (5): 2465-2485. DOI: 10.1007/s42235-023-00356-8

摘要 ( 65 )

Small parasitic Hemipteran insects known as bedbugs (Cimicidae) feed on warm-blooded mammal’s blood. The most famous member of this family is the Cimex lectularius or common bedbug. The current paper proposes a novel swarm intelligence optimization algorithm called the Bedbug Meta-Heuristic Algorithm (BMHA). The primary inspiration for the bedbug algorithm comes from the static and dynamic swarming behaviors of bedbugs in nature. The two main stages of optimization algorithms, exploration, and exploitation, are designed by modeling bedbug social interaction to search for food. The proposed algorithm is benchmarked qualitatively and quantitatively using many test functions including CEC2019. The results of evaluating BMHA prove that this algorithm can improve the initial random population for a given optimization problem to converge towards global optimization and provide highly competitive results compared to other well-known optimization algorithms. The results also prove the new algorithm's performance in solving real optimization problems in unknown search spaces.

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