Biology has been a brilliant teacher and a precious textbook to man-made construction for thousands of years, because it allows one to learn and be inspired by nature’s remarkable and efficient structural systems. However, the emerging biomimetic studies have been of increasing interest for civil engineering design only in the past two decades. Bridge design is one of aspects on structural engineering of biomimetics that offers an enormous potential for inspiration in various aspects, such as the ge-ometry, structure, mechanism, energy use and the intelligence. Recently built bridges and design proposals in which biological systems have produced a range of inspiration are reviewed in this paper. Multidisciplinary cooperation is discussed for the implementation of bio-inspired methods in future design. A case study about using bio-inspired strategy is trying to present a problem-solving approach, yet further cooperation is still needed to utilize biomimetic studies for design inspiration. This paper aims to call a close multidisciplinary collaboration that promotes engineers to build more sustainable and smart structural systems for bridges in the 21st century.

In this paper, a biped water running robot is developed by mimicking the water-running pattern of basilisk lizards. The dynamic mechanism of the robot was studied based on Watt-I planar linkages, and the movement trajectory of the double bar Assur Group was deduced to simulate the water-running foot trajectories of the basilisk lizard. A Central Pattern Generator (CPG)-based fuzzy control method was proposed to control the robot for realizing balance control and gait adjustment. The effectiveness of the proposed control method was verified on the prototype of a water running robot (weight: 320 g). When the biped robot is running on water, the average force generated by the propulsion mechanism is 1.3 N, and the robot body tilt angle is 5?. The experiment results show that the propulsion mechanism is effective in realizing the basilisk lizards-like water running patterns, and the CPG-based fuzzy control method is effective in keeping the balance of the robot.

In this paper, we propose a biomimetic learning approach for motion generation of a multi-joint robotic fish. Based on a multi-joint robotic fish model, two basic Carangiform swimming patterns, namely “cruise” and “C sharp turning”, are extracted as training samples from the observations of real fish swimming. A General Internal Model (GIM), which is an imitation of Central Pattern Generator (CPG) in nerve systems, is adopted to learn and to regenerate coordinated fish behaviors. By virtue of the universal function approximation ability and the temporal/spatial scalabilities of GIM, the proposed learning approach is able to generate the same or similar fish swimming patterns by tuning two parameters. The learned swimming patterns are implemented on a multi-joint robotic fish in experiments. The experiment results verify the effectiveness of the biomimetic learning approach in generating and modifying locomotion patterns for the robotic fish.

Amphibious robots are very attractive for their broad applications in resource exploration, disaster rescue, and recon-naissance. However, it is very challenging to develop the robots for their complex, amphibious working environments. In the complex amphibious environment, amphibious robots should possess multi-capabilities to walk on rough ground, maneuver underwater, and pass through transitional zones such as sandy and muddy terrain. These capabilities require a high-performance propulsion mechanism for the robots. To tackle a complex task, a novel amphibious robot (AmphiHex-I) with,transformable fin-leg composite propulsion mechanisms is developed. With the fin-leg composite propulsions, AmphiHex-I can walk on rough and soft substrates and swim in water with many maneuvers. This paper presents the structural design of the transformable fin-leg propulsion mechanism and its driving module. A hybrid model is used to explore the dynamics between the trans-formable legs and transitional environment such as granular medium. The locomotion performances of legs with various ellip-tical shapes are analyzed, which is verified by the coincidence between the model predictions and the simulation results. Further, an orthogonal experiment is conducted to study the locomotion performance of a two-legged platform walking with an asyn-chronous gait in the sandy and muddy terrain. Finally, initial experiments of AmphiHex-I walking on various lands and swimming in water are implemented. These results verify that the transformable fin-leg mechanisms enable the amphibious robot to pass through a complex, amphibious working environment.

Robots play an important role in underwater monitoring and recovery operations, such as pollution detection, submarine sampling and data collection, video mapping, and object recovery in dangerous places. However, regular-sized robots may not be suitable for applications in some restricted underwater environments. Accordingly, in previous research we designed several novel types of bio-inspired microrobots using Ionic Polymer Metal Composite (IPMC) and Shape Memory Alloy (SMA) ac-tuators. These microrobots possess some attributes of compact structure, multi-functionality, flexibility, and precise positioning. However, they lack the attributes of long endurance, stable high speed, and large load capacity necessary for real-world appli-cations. To overcome these disadvantages, we proposed a mother-son robot system, composed of several microrobots as sons and a newly designed amphibious spherical robot as the mother. Inspired by amphibious turtles, the mother robot was designed with a spherical body and four legs with two Degrees of Freedom (DOF). It is actuated by four vectored water-jet propellers and ten servomotors, and it is capable of walking on land and cruising underwater. We analysed the mother robot’s walking and underwater cruising mechanisms, constructed a prototype, and carried out a series of experiments to evaluate its amphibious motions. Good motion performance was observed in the experiments.

A slat without a cove is built on the basis of a bionic airfoil (i.e. stowed multi-element airfoil), which is extracted from a long-eared owl wing. The three-dimensional models with a deployed slat and a stowed slat are measured in a low-turbulence wind tunnel. The results are used to characterize high-lift effect: compared with the stowed slat, the deployed slat works more like a spoiler at low angles of attack, but like a conventional slat or slot at high angles of attack. In addition, it can also increase stall angle and maximum lift coefficient, and postpone the decrease in the gradient of the lift coefficient. At the same time, the flow field visualized around both three-dimensional models suggests the leading-edge separation associated with the decrease in the gradient of the lift coefficient. Furthermore, the related two-dimensional simulation well agrees with the analysis of the lift coefficient, as the complement to the experiment. The bionic slat may be used as reference in the design of leading-edge slats without a cove.

Many insect families have evolved to produce and detect complex singing patterns for the purposes of mating, display of dominance, predator escape, and other needs. While the mechanisms of sound production by insects have been thoroughly studied, man-machine exploitation of such mechanisms has remained unreported. We therefore describe a method to modulate the frequency spectrum in the chirp call of a singing insect, Gampsocleis gratiosa (Orthoptera: Tettigoniidae), a large katydid indigenous to China and commonly known as Guo Guo or Chinese Bush Cricket. The chirp modulation was achieved through the contact of a ribbon of Ionic Polymer-Metal Composite (IPMC) against wing of the insect. The IPMC effectively served as an actuator when a small DC voltage was applied to the ribbon’s faces.  By applying a sequential on/off voltage waveform to the IPMC ribbon, the katydid’s chirp was modulated in a corresponding manner. This configuration can be used as part of a broader application of using singing insects to harness their acoustic power to produce and propagate machine-induced messages into the acoustic environment.

The abstraction of complex biological lightweight structure features into a producible technical component is a funda-mental step within the transfer of design principles from nature to technical lightweight solutions. A major obstacle for the transfer of natural lightweight structures to technical solutions is their peculiar geometry. Since natural lightweight structures possess irregularities and often have extremely complex forms due to elaborate growth processes, it is usually necessary to simplify their design principles. This step of simplification/abstraction has been used in different biomimetic methods, but so far, it has an arbitrary component, i.e. it crucially depends on the competence of the person who executes the abstraction. This paper describes a new method for abstraction and specialization of natural micro structures for technical lightweight compo-nents. The new method generates stable lightweight design principles by using topology optimization within a design space of preselected biological archetypes such as diatoms or radiolarian. The resulting solutions are adapted to the technical load cases and production processes, can be created in a large variety, and may be further optimized e.g. by using parametric optimization.

Tamarisk, a plant that thrives in arid and semi-arid regions, has adapted to blustery conditions by evolving extremely ef-fective and robust anti-erosion surface patterns. However, the details of these unique properties and their structural basis are still unexplored. In this paper, we demonstrate that the tamarisk surface only suffers minor scratches under wind–sand mixture erosion. The results show that the anti-erosion property of bionic sample, inspired by tamarisk surface with different surface morphologies, can be attributed to the flow rotating in the grooves that reduces the particle impact speed. Furthermore, the simulation and experiment on the erosion wear behavior of the bionic samples and bionic centrifugal fan blades show that the bionic surface with V-type groove exhibits the best erosion resistance. The bionic surface on centrifugal fan blades with opti-mum parameters can effectively improve anti-erosion property by 28.97%. This paper show more opportunities for bionic application in improving the anti-erosion performance of moving parts that work under dirt and sand particle environment, such as helicopter rotor blades, airplane propellers, rocket motor nozzles, and pipes that regularly wear out from erosion.

The Sit-to-Stand (STS) is an activity most people perform numerous times daily. Standing up deals with the transition from two stabilized postures, namely seated to standing, with movement of all body segments except the feet. During the STS the body’s Center of Gravity (COG) is moved upward from a sitting position to a standing position without losing balance and requiring a good coordination of many muscles. Three main phases of the STS movement can be recognized. One begins to stand up by inclining the upper body forward, which moves body mass toward the feet in order to maintain balance after lift-off. Prior to leaving the chair, hip and knee extensor muscles are activated to provide antigravity support for these joints, this action is commonly referred to as “weight shift”. Finally, after leaving the chair, the leg and trunk joints are straightened to achieve upright stance. The STS task can be considered of major importance for impaired and elderly people to achieve minimal mo-bility and independence. In this paper we detail a procedure for the design of assisting devices to be used for the STS. In par-ticular, an experimental procedure is described firstly to track and record point trajectories and the orientation of the trunk during the STS. This analysis is then used to get information for the design of assisting devices. A proposal and simulation results are presented for a novel mechatronic system. In particular, for the case under study experimental tests are used to drive the actua-tion system for the reported simulation. A functional mechatronic scheme is then proposed to control the device during its operation.

The serrated incisors of grasshopper [Chondracris rosea rosea (De Geer)] possess an advantageous capacity for cutting plant fiber. Inspired by this special geometrical structure of incisors, bionic saw blade was designed and manufactured. MATLAB software digital image processing technology was used to obtain outer margin profile from stereomicroscope pho-tograph of the serrated incisors. The outer margin profile of incisors was fitted and expressed by six-order polynomial function. To compare the cutting capacity of bionic and traditional saw blades, the internodes of dry corn stalks were cut perpendicularly. Cutting force-deformation characteristics were obtained by universal testing machine. The results of cutting experiments show that the maximum cutting force of bionic saw blade was 128.26 N, which is 15.87% lower than 152.45 N of traditional saw blade; the average cutting force of bionic saw blade was 51.56 N, which is 28.17% less than 71.78 N of traditional saw blade. Meanwhile, the cutting energy consumption of bionic saw blade was 8.95 J, which is 12.85% less than 10.27 J of traditional saw blade. Overall, the bionic saw blade can lead to noticeable reduction of the cutting force and energy. These results will be helpful for designing cutting elements of corn stalk harvesting, biomass size reduction and other processing machinery.

A pelvic endoprosthesis is the primary means of pelvic reconstruction after internal hemipelvectomy. In this study, a novel biomimetic hemipelvic prosthesis, including an artificial ilium, an artificial acetabulum, and an artificial pubis, was developed. A Finite Element Method (FEM) was carried out to investigate the biomechanical performance of a pelvis reconstructed with biomimetic hemipelvic prosthesis. Two models, including the reconstructed pelvis and the original pelvis (control model), were established according to the geometry from CT data of a human male patient with pelvic bone sarcomas. The FE models predict that the biomechanical function of the pelvic ring can be reestablished using this prosthesis. Results show that the body force loaded on the S1 vertebra is restored and transferred towards the sacro-iliac joint, and along the ilium onto the bearing surface of the artificial ilium, then to the artificial acetabulum and pubis. Von Mises stresses observed in this reconstructed pelvis model are still within a low and elastic range below the yielding strength of cortical bone and Ti6Al4V. The values of deformation and strain of the reconstructed pelvis are close to the data obtained in the original pelvis. With the partial replacement of the pubis, little influence is found towards the pubis symphysis. However, the interface between the prosthesis and pelvic bone may become the critical part of the reconstructed pelvis due to the discontinuity in the material properties, which results in stress shielding and deformation constraining. So a biomimetic flexible connection or inter layer to release the deformation of pelvis is suggested in future designing.

Biomaterials have attracted more attention from biomedical research in recent years. Yet there are still unmet demands for current biomaterials, such as the reduction of local inflammation of the implantation site. Poly-Propylene Carbonate (PPC), a polymer with ester bonds on CO2 backbone, degrades to CO2 and water, which are natural components of human body, yielding less inflammatory response than traditional biomaterials. However, the tensile strength and heat resistance properties of PPC are less ideal. In order to improve the properties of PPC, we have developed a new PPC (M-PPC), modified by mixing with Poly-3-Hydroxybutyrate (PHB). Here, we report the biodistribution profiles of PPC and M-PPC, their biocompatibility and toxicity. 125I-radiolabeled PPC and M-PPC were prepared and their biodistribution in Balb/c mice were investigated. Then acute systemic toxicity and haemolysis assays were conducted to study their toxicity and biocompatibility respectively. Results show that M-PPC has a good potential to be used as bone repair materials because it possesses typical biodistribution pattern in major organs, minimal toxicity and good biocompatibility.

Articular cartilage lubricates the contact surfaces in human joints and provides a shock-absorbing effect which protects the joint under dynamic loading. However, this shock-absorbing effect is gradually reduced as the result of normal wear, tear and aging-related cartilage loss. Thus, with the increasing average human life expectancy, the issue of joint health has attracted significant interest in recent decades. In developing new materials for the repair or regeneration of damaged articular cartilage, it is essential that the difference in the mechanical properties of healthy and damaged cartilages is well-understood. In the present study, the hardness and Young’s modulus of damaged and healthy porcine articular cartilage samples are evaluated via a quasi-static nanoindentation technique. A dynamic mechanical analysis method is then applied to determine the viscoelastic properties of the two samples. The results presented in this study provide a useful insight into the mechanical properties of articular cartilage at the mesoscale, and therefore fill an important gap in the literature.

To obtain accurate search results and advocate the use of human effort in discovering knowledge, we propose a method based on Ant Colony Algorithm (ACA). The proposed method simulates the behavior of ants searching for food. Specific features such as the behavior of ants searching for food, their established search paths, and the ant “neighborhood” profile are investigated. The investigation results reveal that the behavior of people searching for useful information resembles that of ants searching for food. We also use semantic annotation and the decreasing matrix dimension approach to accelerate the food searching process and shorten the distance between the query starting points and the ultimate answers. A user behavior model is constructed based on personal and domain ontologies. Experimental evaluation with the enhanced ACA has two parts: (1) estimating the efficiency of information retrieval with user interests considered and (2) identifying how to weigh usage and rate user data during recommendation.