Bioinspiration & Biomimetics最新文献

Smart agriculture tools as well as advanced studies on agrochemicals and plant biostimulants aim to improve crop productivity and more efficient use of resources without sacrificing sustainability. Recently, multiple advanced sensors for agricultural applications have been developed, however much less advancement is reported in the field of precise delivery of agriculture chemicals. The organic electronic ion pump (OEIP) enables electrophoretically-controlled delivery of ionic molecules in the plant tissue, however it needs external power-supplies complicating its application in the field. Here, we demonstrate that an OEIP can be powered by wind-driven leaf motion through contact electrification between a natural leaf and an artificial leaf. This plant-hybrid triboelectric nanogenerator (TENG) directly charges the OEIP, enabling proton delivery into a pH indicator solution, which triggers visible color changes as a proof-of-concept. The successful delivery of up to 44 nmol of protons was revealed by pH measurements after 17 h autonomous operation in air flow moving the plant and artificial leaves. Several control tests indicated that the proton delivery was powered uniquely by the charges generated during leaf fluttering. The OEIP-TENG combination opens the potential for targeted and self-powered long-term delivery of relevant chemicals in plants, with the possibility of enhancing growth and resistance to abiotic stressors.

The propulsive fins of ray-finned fish are used for large scale locomotion and fine maneuvering, yet also provide sensory feedback regarding hydrodynamic loading and the surrounding environment. This information is gathered via nerve cells in the webbing between their fin rays. A similar bioinspired system that can gather force feedback from fin motion could enable valuable insight into robotic underwater locomotion improving swimming efficiency and orientation. Fins are largely composed of bendable rays that support an elastic membranous web. In this investigation we have produced a stretch-sensing web that can be used as a sensor for a robotic fin; a proprioceptive fin webbing capable of measuring hydrodynamic loads. Our soft capacitive sensor web is embedded in 350 µm thin film that is held between wires which emulate fin rays. These sensor web constructs were successfully tested in water tunnels and maintained their sensory performance at speeds up to 0.7 m/s and at angles-of-attack up to 90 degrees. We demonstrated sensor response as a function of water speed and angle of attack. Induced vibrations in the membrane from vortex shedding and flutter at high speeds were mitigated through the addition of passive chordwise stiffeners and tensioning of the membrane was investigated. Through understanding sensing membrane behavior in flow, the development of specialized fin webbing sensors becomes possible. This invention thus presents a milestone in advanced hydrodynamic sensing in fish robots enabling us to push further towards autonomous control loops in fish robots. .

An experimental study was carried out to investigate the effects of biomimetic vortex generators (biomimetic-VGs) on the aerodynamic performance of the NACA0015 airfoil. Aerodynamic force measurements and titanium dioxide (TiO₂) based flow visualization technique experiments were performed for test models at Re=1.2×10⁵. Aerodynamic force measurement experiments were carried out in the wind tunnel at angles of attack of 0°-18° with an increment of 1°. As a result of the experiments, it was revealed that the lift coefficient (C_L) increased and the drag coefficient (C_D) decreased by using the seaconchshell structure as a vortex generator for the wing model. In addition, it has been observed that biomimetic models were shifted stall angle of the airfoil by 1°. In the surface oil flow visualization experiment results, the flow structure around the NACA0015 airfoil of biomimetic models (BMs) was revealed and interpreted. Moreover, it has been revealed that the aerodynamic performance of the airfoil increases as a result of the use of BMs. It is also revealed that the seaconchshell structure, which has not been studied before in the literature and which is the subject of this study, can be used as an effective flow control device.

Flying insects have a robust flight system that allows them to fly even when their forewings are damaged. The insect must adjust wingbeat kinematics to aerodynamically compensate for the loss of wing area. However, the mechanisms that allow insects with asynchronous flight muscle to adapt to wing damage are not well understood. Here, we investigated the phase and amplitude relationships between thorax deformation and flapping angle in tethered flying bumblebees subject to wing clipping and weighting. We used synchronized laser vibrometry and high-speed videography to measure thorax deformation and flapping angle, respectively. We found that changes in wing inertia did not affect thorax deformation amplitude but did influence wingbeat frequency. Increasing wing inertia increased flapping amplitude and caused a phase lag between thorax deformation and flapping angle, whereas decreasing wing inertia did not affect flapping amplitude and caused the flapping angle to lead thorax deformation. Based on our findings, we proposed a qualitative model of the insect flight system. This model suggests insects leverage a wing hinge-dominated vibration mode to fly, and highlights the possibility of a disproportionate damping between the wing hinge and thorax when the insect's wings are clipped. The results of our study provide insights into the robust design of insect-inspired flapping wing micro air vehicles.

We improve the aerodynamic performance of a simplified vertical-axis wind turbine (VAWT) using a biomimetic flap, inspired by the movement of secondary feathers of a bird's wing at landing (Liebe 1979Aerokurier1254). The VAWT considered has three NACA0018 straight blades at the Reynolds number of80000based on the turbine diameter and free-stream velocity. The biomimetic flap is made of a rigid rectangular curved plate, and its streamwise length is 0.2cand axial (spanwise) length is the same as that of blade, wherecis the blade chord length. This device is installed on the inner surface of each blade. Its one side is attached near the blade leading edge (pivot point), and the other side automatically rotates around the pivot point (without external power input) in response to the surrounding flow field during blade rotation. The flap increases the time-averaged power coefficient by 88% at the tip-speed ratio of 0.8, when its pivot point is at 0.1cdownstream from the blade leading edge. While the torque on the blade itself does not change even in the presence of the flap, the flap itself generates additional torque, thus increasing the overall power coefficient. The phase analysis indicates that the power coefficient of VAWT significantly increases during flap opening to full deployment through the interaction with vortices separated from the blade leading edge. When the pivot point of flap is farther downstream from the leading edge or the flap operates at a high tip-speed ratio, the performance of the flap diminishes due to its weaker interaction with the separating vortices.

Inching-locomotion caterpillars (ILAR) inspire the design of 'inch-worm' robots with biomimicry features, that can be adapted to different environments, such as natural, man-made, or other planets. Therefore, this work defines a novel mathematical method called Multi-Body Dynamics for Inching-Locomotion Caterpillar Robots (MBD-ILAR) to standardize the gait simulation of this type of machines, including a payload over the head to carry an object. The method is composed of 3 steps: (i) setting the model, where the input data is defined by: the phases of walk-stride (PHAWS) based on the bioinspired robotic design (BIROD) method, linkage dimensions of insect's morphology based on the geometrical kinematic analysis (GEKINS) algorithm, the joint types, the link's mass and center of mass, and the gravity constant. Then, (ii) kinematic analysis: to solve the orientation, velocity, and acceleration; and (iii) dynamic analysis: to obtain the joint forces, attachment forces to the ground, motor's torque, and mechanical power. The method was applied in a case study adapting the dimensions of a real specimen-Geometridae sp.(35 000 species), for that purpose, a graphical user interface (GUI) was developed in order to get the biomechanical results that guarantee the robot's actuator selection: (a) attachment mechanisms: vacuum pumps with suction cups (SC) or electromagnets (EM), and (b) joints: electromechanical rotary servomotors. Finally, to validate the numerical approach of MBD-ILAR, we performed an influence study of model parameters: link's length, link's mass, and gravity on the behavior of the attachment forces to the ground, torque, and mechanical power. The future method's application is expected to be useful to complete the phase of the computational robotic design before the physically mechatronic implementation; in addition, it could be adapted to other arthropods.

This study focuses on improving coordination among teams of heterogeneous robots, including Unmanned Aerial Vehicles (UAVs) and Unmanned Ground Vehicles (UGVs), drawing inspiration from natural pack-hunting strategies. The goal is to increase the effectiveness of rescue operations using a new framework that combines hierarchical decision making with decentralised control. The approach features dynamic target assignment and real time task allocation based on a scoring function that considers multiple factors, such as the distance to the target, energy usage, communication ability, and potential for energy exchange. In contrast to methods that use static roles, this system allows robots to change between 'Chaser' and 'Flanker' roles based on current data, improving adaptability. Results showed that this approach led to better coordination and decision-making, with robots autonomously adjusting their roles to improve mission outcomes. The findings suggest that combining hierarchical structures with decentralised control improves responsiveness and ensures the effective use of resources in complex, changing environments, making this method well-suited for real-world rescue operations.

Behaviors of animal bipedal locomotion can be described, in a simplified form, by the bipedal spring-mass model. The model provides predictive power, and helps us understand this complex dynamical behavior. In this paper, we analyzed a range of gaits generated by the bipedal spring-mass model during walking, and proposed a stabilizing touch-down condition for the swing leg. This policy is stabilizing against disturbances inside and outside the same energy level and requires only internal state information. In order to generalize the results to be independent of size and dimension of the system, we nondimensionalized the equations of motion for the bipedal spring-mass model. We presented the equilibrium gaits (a.k.a fixed point gaits) as a continuum on the walking state space showing how the different types of these gaits evolve and where they are located in the state space. Then, we showed the stability analysis of the proposed touch-down control policy for different energy levels and leg stiffness values. The results showed that the proposed touch-down control policy can stabilize towards all types of the symmetric equilibrium gaits. Moreover, we presented how the peak leg force changes within an energy level and as it varies due to the type of the gait since peak force is important as a measurement of injury or damage risk on a robot or animal. Finally, we presented simulations of the bipedal spring-mass model walking on level ground and rough terrain transitioning between different equilibrium gaits as the energy level of the system changes with respect to the ground height. The analysis in this paper is theoretical, and thus applicable to further our understanding of animal bipedal locomotion and the design and control of robotic systems like ATRIAS, Cassie, and Digit.

A beluga-like model of click train signal is developed by observing beluga's sound recording. To reproduce the feature of the biosonar signal, this paper uses a signal extracting method with a correction factor of inter-click interval to acquire the parameter of click trains. The extracted clicks were analyzed in the time and frequency domain. Furthermore, a joint pulse-frequency representation was undertaken in order to provide a 2D energy distribution for an echolocation click train. The results from joint pulse-frequency representation indicate that click train can be adjusted its energy distribution by using a multi-component signal structure. To evaluate the capability of the click train to inform the whale of relevant target information perception for the click train, a finite element model is built to reproduce target discrimination by the bio-inspired click train. Numerical results indicate that the bio-inspired click train could enhance the echo-response by concentrating energy into the frequency bins for extracting target feature effectively. This proof-of-concept study suggests that the model of click train could be dynamically controlled to match the target properties, and show a promising way to use various types of echolocation click train to interrogate different features of the target by man-made sonar.

This paper presents the design of an underactuated adaptive humanoid Manipulator (UAHM) featuring a link-spring telescopic rod-slide mechanism, which is capable of basic human-like grasping functions. Initially, the mechanical structure of the UAHM is introduced, with a detailed exposition of its transmission mode, finger architecture, and overall configuration. Subsequently, the kinematic and static models of the UAHM are delineated, elucidating the relationship between the phalangeal contact forces, contact positions, and bending angles during both fingertip and envelope grasping. Finally, the experimental platform has been established, and the UAHM prototype has undergone testing, demonstrating commendable dexterity, adaptability, and grasping capabilities. Furthermore, the results of comparative numerical analyses corroborate the validity of the static model.