Bioinspiration & Biomimetics最新文献

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.

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.

Prior spring-mass locomotion models achieve stable gaits by prescribing a constant touchdown angle (TD angle) during the flight phase; however, they either exclude torso modeling or depend on online state feedback to stabilize the pitch angle of the torso. In contrast, evidence from biology and robotics suggests that coordinating monoarticular and biarticular hip-knee muscles supports whole-body stability with the simplified controller without online state feedback. However, this has only been verified through empirical and constructive approaches, rather than through dynamical modeling. To verify this hypothesis, we propose a new mathematical dynamical model, torso-hip-knee three pairs of six springs, a planar locomotion model that consists of a torso and coordinated springs imitating a three-pair six-muscle structure in the upper leg. The proposed dynamical model achieves stable running solely by giving a constant TD angle and a constant kicking angle relative to the torso, which control the dynamics during the flight and stance phases respectively. Numerical analysis utilizing Floquet multipliers demonstrates that self-stability emerges across stiffness parameters of coordinated springs. These results constitute the first mathematical evidence that muscle coordination, including biarticular muscles, can stabilize torso pitch during locomotion and provide guidelines for legged-robot design and rehabilitation assessment.

Environmental stressors such as hypoxia challenge the balance between individual physiological performance and the coordination required for collective behaviors like schooling. Here, we investigate how glass catfish (Kryptopterus vitreolus) modulate locomotor and group-level behavior across a gradient of oxygen saturation (95%-20%) while swimming steadily at a constant cruising speed. We found that tailbeat frequency decreased significantly with declining oxygen (p < 0.0001), alongside reductions in wave speed (p = 0.007). Tailbeat amplitude, by contrast, increased significantly under hypoxia (p < 0.0001), and posterior segment angles showed a slight, non-significant increase, consistent with modestly greater tail bending. Despite these changes, the Strouhal number remained fairly constant, and waveform topology was conserved. School structure, including nearest-neighbor distance and distance to the center of the school, remained stable across oxygen treatments, but with significant variation across individual schools. A clear behavioral threshold was observed below 25% oxygen saturation, beyond which coordinated schooling deteriorated. These findings demonstrate that glass catfish employ internally coordinated, energetically economical kinematic adjustments to preserve group cohesion under metabolic constraint. This strategy highlights a decentralized mechanism for sustaining collective behavior near physiological limits and offers biologically-grounded insights relevant to energy-aware coordination in bioinspired swarms.

Satellite telemetry is widely used to study the movements of marine mammals, but current attachment methods for seals typically rely on epoxy adhesives, which pose risks to animal welfare and the marine environment. This study presents a biomimetic, adhesive-free attachment system inspired by the seal louseEchinophthirius horridus, an ectoparasite capable of maintaining a strong grip on seal fur in aquatic conditions. A top-down biomimetic approach was used to abstract key functional principles from the louse's claw morphology and cuticular anchoring structures. These biological features informed the development of a 3D-printed comb-clamp prototype, termed 'TACS' (Transmitter Attachment Clamp[s]), designed specifically for the hair structure of harbour seals. Microscopy and x-ray microtomography revealed morphological traits such as interlocking setae, directional grooves, and a specialised euplantula, which were functionally integrated into the prototype. Tensile tests on tanned seal fur demonstrated mean maximum retention forces of 4.58 N under dry conditions and 2.42 N under wet conditions. A proof-of-concept trial on a live harbour seal showed successful attachment for up to 50 min, without signs of distress or fur damage. The TACS system fulfilled key design criteria: rapid and reversible application, low material weight (<20 g), and strong mechanical retention without the use of adhesives. This study demonstrates the potential of biologically inspired design to provide an environmentally responsible alternative to conventional tagging methods and highlights the relevance ofE. horridusas a functional model for bioinspired gripping systems in marine applications.

The mechanism of wake formation behind two staggered in-phase pitching foils is numerically investigated over a range of Strouhal numbers (0.15

With the rapid advancements in automation and soft robotics, the exploration of mobile robots for applications in complex environments is increasingly deepening. This paper presents a novel dual soft arm mobile robot (DSAMR), whose design integrates advanced soft robotics technologies with biomimetic design inspired by human arms, aiming to achieve efficient obstacle avoidance and object manipulation. The robot employs Bubble Artificial Muscle Arms (BAMAs) for locomotion, enabling flexible movements such as forward, backward, and turning motions; it also integrates TacTip (tactile fingertip), a biomimetic sensor that mimics the tactile structure of human fingertips, to achieve real-time perception. BAMAs and TacTip collaborate to achieve the integration of perception and operation like a human hand, enabling the system to accurately detect obstacles and manipulate objects, including typical delicate items such as a paper towel roll and a pen, with the maximum capacity to grasp objects weighing up to 148.8 g. Experiments have demonstrated that a single inflation-deflation cycle of the BAMAs enables the DSAMR to turn right by 35.5° and left by 28.3°, and successfully allows the DSAMR to recognize obstacles and turn to avoid them. The experimental results indicate that the DSAMR can operate effectively in dynamic environments, with excellent stability and obstacle avoidance capabilities. This paper discusses the design details of BAMA actuators, steering engines, and TacTip, as well as their integration into the robot's motion and sensing systems. The findings emphasize the DSAMR's potential applications in industrial automation, particularly in the context of Industry 4.0. Finally, the study summarizes optimization strategies and future improvement directions to enhance the robot's operational efficiency, including onboard power integration and advanced obstacle recognition technologies.

Research on dolphins dates back nearly 90 years to the well-known Gray's Paradox, which proposed that dolphins are capable of swimming at speeds that seemingly exceed their energetic limits. Inspired by microvibrations observed on dolphin skin, longitudinal micro-ultrasonic waves (LMUWs)-a form of dynamic skin vibration-have been shown to significantly reduce drag. This finding motivated our investigation into how these vibrations affect swimming performance under dolphin-like, tail-driven propulsion. In this study, we develop a conceptual two-dimensional computational fluid dynamics model that integrates dynamic skin microvibrations with tail fluke propulsion to systematically explore dolphin swimming dynamics. Two modes of skin vibration are examined: downstream-traveling LMUW (DTLMUW) and upstream-traveling LMUW (UTLMUW). The results demonstrate that DTLMUW enhances net thrust and accelerates swimming, whereas its cessation leads to a speed reduction. Conversely, UTLMUW causes deceleration during application but results in a speed increase once stopped. Therefore, to achieve net acceleration, a longer duration of DTLMUW but a shorter UTLMUW period is most effective. This approach aligns with the optimal interaction between skin motion and the surrounding flow. Moreover, once skin vibrations cease, the forces acting on the model quickly return to their non-vibrating baseline, allowing tail-driven propulsion to maintain the speed gains induced by LMUWs. As the frequency of vibration pulses increases, the acceleration effect becomes cumulative, further boosting overall performance. This study provides new insights into the mechanisms behind dolphins' high-speed swimming and offers valuable guidance for the design and optimization of bioinspired propulsion systems.

Salps are underwater invertebrates considered to be among the world's most energy-efficient examples of jet propulsion. They can swim as solitary individuals or as physically connected colonies, coordinating their jets to produce collective movement. Inspired by salps, we developed the SALP (Salp-inspired Approach to Low-energy Propulsion) system, where individual SALP robots can be physically connected into a multi-SALP group, and we investigate the coupled effects of physical arrangement and jet coordination on the swimming performance and energy efficiency of a two-SALP system. We conduct free swimming tests to evaluate locomotion performance metrics and find that the two-SALP system, when properly coordinated, is able to swim with 15.7% higher speed and 11.3% lower cost of transport than the single SALP. Supporting flow characterization experiments using particle image velocimetry reveal vortex ring structures emanating from robot SALP nozzles. The data suggest that propulsion performance is affected by the spatial arrangement of the vortex ring structure. In particular, we find that SALP systems that produce a parallel vortex ring arrangement produce less vortex circulation and impulse than an in-series vortex ring arrangement. Overall, the SALP system is a useful platform for exploring salp-inspired multi-jet locomotion strategies, enabling decoupling of physical and control parameters to expose underlying locomotion physics in ways that are difficult with the biological salp. These insights advance our understanding of multi-jet locomotion and support the development of more energy-efficient jet-propelled underwater robots in the future.

Energy efficiency is one of the main concerns in the design of embedded circuits, especially considering the ever-growing amount of portable devices produced for specialized to everyday life applications. Taking inspiration from neuronal processes in the brain, neuromorphic systems are seen as promising solutions to this concern. Great advances in all fields led to the production of numerous hardware implementations, digital or mixed-signal for the most part. While digital systems showcase high accuracy performances and an advanced technological maturity, they fail to reach the ultra-low power (ULP) consumptions of emerging technologies or fully analog implementations due to generally non-dedicated chips and bulky hardware. In this work, we designed and implemented a bioinspired analog demonstrator of inter-pulse delay detection on standard complementary metal oxide semiconductor in the subthreshold operation mode. Relying on the temporal pattern recognition mechanism in female field crickets, our circuit reach on average 750 pW of total power consumption under probes during detection on real-world recordings of male crickets calling song. The circuit was evaluated in quiet, noisy, and multi-source environments, demonstrating strong detection performances given its sparse architecture and ULP consumption.