Journal of Bionic Engineering最新文献

This study examines the locomotor biomechanics of the giant panda (Ailuropoda melanoleuca), a species of profound ecological and evolutionary significance. Despite its characteristic slow movement and non-sprinting locomotion, the panda has endured for over 8 million years, offering a unique perspective on the evolution of mammalian locomotion. Through comprehensive gait analysis and ground reaction force measurements, we investigate the functional distinctions between the forelimbs and hind limbs, highlighting the biomechanical underpinnings of its plantigrade locomotion. Our findings reveal how the panda’s limb structure and movement patterns contribute to energy efficiency, particularly during slow locomotion. By comparing these results with those of other large mammals, such as grizzly bears (Ursus arcto), we explore the role of limb mechanics in energy conservation. Additionally, we assess the locomotor performance of pandas across different age groups, shedding light on the maturation of locomotor abilities and the potential adaptive significance of their slow, deliberate movement. This research offers novel insights into the biomechanics of panda locomotion and its evolutionary implications, furthering our understanding of the functional evolution of bear species and informing conservation strategies for this iconic species.

This paper presents a template-based control method for achieving diverse trotting motions in quadrupedal systems, with a focus on smooth transitions between walking trot, regular trot, and flying (running) trot. First, we extend the Clock Torque Actuated Spring-Loaded Inverted Pendulum (CT-SLIP) template to three dimensions, creating a comprehensive control framework. A template-based control strategy is then developed to compute joint torques for stable locomotion, along with a detailed approach for transitioning between gaits. To enable the flight phase in the running trot, a projectile motion model is incorporated into the template. For improved turning, we implement a yaw control method that rotates the swing foot plane to enhance stability, enabling higher turning rates while maintaining steady forward motion and balance. To further enhance locomotion stability and performance, a Whole-Body Controller (WBC) is integrated. The proposed method is implemented and rigorously evaluated in the MuJoCo simulator, with experiments testing gait transitions and disturbance rejection. Additionally, comparative studies assess the impacts of both swing foot plane rotation and the WBC on overall system performance. Furthermore, the approach is validated through real hardware experiments on Unitree GO1 quadrupedal robot, successfully demonstrating smooth gait transitions, stable locomotion, and practical applicability in real-world scenarios.

This paper presents a novel rehabilitation robot designed to address the challenges of Passive Range of Motion (PROM) exercises for frozen shoulder patients by integrating advanced scapulohumeral rhythm stabilization. Frozen shoulder is characterized by limited glenohumeral motion and disrupted scapulohumeral rhythm, with therapist-assisted interventions being highly effective for restoring normal shoulder function. While existing robotic solutions replicate natural shoulder biomechanics, they lack the ability to stabilize compensatory movements, such as shoulder shrugging, which are critical for effective rehabilitation. Our proposed device features a 6 Degrees of Freedom (DoF) mechanism, including 5 DoF for shoulder motion and an innovative 1 DoF Joint press for scapular stabilization. The robot employs a personalized two-phase operation: recording normal shoulder movement patterns from the unaffected side and applying them to guide the affected side. Experimental results demonstrated the robot’s ability to replicate recorded motion patterns with high precision, with Root Mean Square Error (RMSE) values consistently below 1 degree. In simulated frozen shoulder conditions, the robot effectively suppressed scapular elevation, delaying the onset of compensatory movements and guiding the affected shoulder to move more closely in alignment with normal shoulder motion, particularly during arm elevation movements such as abduction and flexion. These findings confirm the robot’s potential as a rehabilitation tool capable of automating PROM exercises while correcting compensatory movements. The system provides a foundation for advanced, personalized rehabilitation for patients with frozen shoulders.

In clinical work, many soft medical pipelines are located deep within the body, resulting in a lack of feedback regarding bending or folding conditions, which presents significant challenges for medical staff. To solve the problem, this study innovatively designs a flexible bending sensor, which can be attached to the medical pipelines and monitor the bending conditions. Based on a flexible substrate with secondary microstructures copied from champagne rose petals, the interdigital electrodes are designed to enhance the sensitivity of the sensor due to the amplifying effect. A high sensitivity of 2.209%⁻¹in a bending strain range of 8.9%, and a stable repeatability for over 6000 cycles under 1.8% bending strain are achieved by the sensor. By integrating the bending sensor, here, the nasogastric tube, femoral vein catheter, and tracheal intubation are used to demonstrate the sensing performance. Additionally, during the measurement, the sensing signals are processed and transformed to the bending angles simultaneously, enabling the direct visualization of the bending conditions of the pipelines. This work proposes innovative applications for bending sensors in medical technology and establishes a foundation for further research on flexible bending sensors.

Formation control remains a critical challenge in cooperative multi-agent systems, particularly for Unmanned Underwater Vehicles (UUVs). Conventional approaches often suffer from several limitations, including reliance on global information, limited adaptability, high computational complexity, and poor scalability. To address these issues, we propose a novel bio-inspired formation control method for UUV swarms, drawing inspiration from the self-organizing behavior of fish schools. Our method integrates three key components: (1) a coordinated motion strategy without predefined targets that enables individual UUVs to align their movements via simple left or right rotations based solely on local neighbor interactions; (2) a target-directed movement strategy that guides UUVs toward specified regions; and (3) a dispersion control strategy that prevents overcrowding by regulating local spatial distributions. Simulation results confirm that the method achieves robust formation control and efficient area coverage using only local perception. Validation in a 9-UUV simulation environment demonstrates the approach’s flexibility, decentralization, and computational efficiency, making it particularly suitable for large-scale swarms with limited sensing and processing capabilities.

Tree knots are generally considered defects in wood, but how the surrounding structures of the defects affects strength of wood has not been studied. Here the mechanical properties of static compression and hole bearing tests were designed for encased knots and intergrown knots, and the strengthening mechanism of streamline tissue and connecting interface was analyzed by finite element modeling. And the two reinforced structures were applied to composite structural holes and connecting holes, which significantly improved open hole compressive strength and hole bearing strength. And the finite element models for two kinds of composite hole were created to analyze how the stress field around the reinforced structure strengthens the composite. Both the experimental results and the finite analysis results show that the streamline structure could effectively improve the compressive properties of composite structural holes, and the connecting interface provided a stable constraint for giving full play to the hole bearing properties of stronger materials. These two structures will provide reference for the structural design of lightweight composites.

Surface morphology of Ceratocanthus beetle elytra was investigated for spike surface texture and its geometry using Scanning Electron Microscopy (SEM). Material properties were analyzed for both surface and cross-section of elytra using nano-indentation technique. The spike texture was significantly rigid compared with the non-textured zone; a bi-layer system of E and H was identified at the elytra cross-section. Normal load acting on spike texture during free-fall conditions was estimated analytically and deflection equation was derived. The design of spike texture with conical base was studied for minimization of deflection and volume using the Non-dominated Sorting Genetic Algorithm (NSGA-II) optimization technique, confirming the smart design of the natural solution. The frictional behavior of elytra was studied using fundamental tribology test and the role of the oriented spike texture was investigated for frictional anisotropy. Compression resistance of full beetle was evaluated for both conglobated and non-conglobated configuration and tensile strengths were compared using Brazilian test. Puncture and wear resistance of full elytra were characterized and correlated with its defense mechanism.

Locomotion performance degradation after carrying payloads is a significant challenge for insect-scale microrobots. Previously, a legged microrobot named BHMbot with a high load-carrying capacity based on front-leg actuation configuration and efficient running gait was proposed. However, insects, mammals and reptiles in nature typically use their powerful rear legs to achieve rapid running gaits for predation or risk evasion. In this work, the load-carrying capacity of the BHMbots with front-leg actuation and rear-leg actuation configurations is comparatively studied. Simulations based on a dynamic model with four degrees of freedom, along with experiments, have been conducted to analyze the locomotion characteristics of the two configurations under different payload masses. Both simulation and experimental results indicate that the load-carrying capacity of the microrobots is closely related to their actuation configurations, which leads to different dynamic responses of the microrobots after carrying varying payload masses. For microrobots with body lengths of 15 mm, the rear-leg actuation configuration exhibits a 31.2% enhancement in running speed compared to the front-leg actuation configuration when unloaded. Conversely, when carrying payloads exceeding 5.7 times the body mass (350 mg), the rear-leg actuation configuration demonstrates an 80.1% reduction in running speed relative to the front-leg actuation configuration under the same payload conditions.

Flexible pressure sensors have excellent prospects in applications of human-machine interfaces, artificial intelligence and human health monitoring due to their bendable and lightweight characteristics compared to rigid pressure sensors. However, arising from the limited compressibility of soft materials and the hardening of microstructures at the device interface, there is always a trade-off between high sensitivity and broad sensing range for most flexible pressure sensors, which results in a gradual saturation response and limits their practical applications. Herein, inspired by the distinct pressure perception function of crocodile receptors, a highly sensitive and wide-range flexible pressure sensor with multiscale microdomes and interlocked architecture is developed via a facile PS-decorated molding method. Combined with interlocked architecture, the multiscale dome-shaped structured interface enhances the compressibility of the material through structural complementarity, increases the contact area between functional materials, which compensates for the stiffness induced by the deformation of dense microscale columns. This effectively mitigates structural hardening across a wide pressure range, leading to the overall high performance of the sensor. As a result, the obtained sensor exhibits a low detection limit of 5 Pa, a high sensitivity of 6.14 kPa^− 1, a wide measurement range up to 231 kPa, short response/recovery time of 56 ms/69 ms, outstanding stability over 10,000 cycles. Considering these excellent properties, the sensor shows promising potential in health monitoring, human-computer interaction, wearable electronics. This study presents a strategy for the fabrication of flexible pressure sensors exhibiting high sensitivity and a wide pressure response range.

Reducing the resistance of vehicles, ships, aircraft and other means of transport during movement can significantly improve the speed, save energy and reduce emissions. After billions of years of continuous evolution, organisms in nature have gradually developed the ability to move at high speed to achieve better survival. These evolved organisms provide a perfect template for the human development of drag reduction materials. Revealing the unique physiological structural characteristics of organisms and their relationship with resistance during movement can provide a feasible approach to solving the problem of reducing friction resistance. Whether flying in the sky, running on the ground, swimming in the water, or even living in the soil, many creatures in various environments have the ability to reduce resistance. Driven by these inspirations, researchers have done a lot of work to explore and imitate these biological epidermis structures to achieve drag reduction. In this paper, the biomimetic drag reduction materials is introduced in detail in the order of drag reduction mechanism, structural characteristics of biological epidermis (including marine animals, flying animals, soil animals and plants), biomimetic preparation methods, performance testing methods and application fields. Finally, the potential of various biomimetic drag reduction materials in engineering application and the problems to be overcome are summarized and prospected. This paper can help readers comprehensively understand the research progress of biomimetic drag reduction materials, and provide reference for further designing the next generation of drag reduction materials.