This paper presents a novel, legged robot, Abigaille-III, which is a hexapod actuated by 24 miniature gear motors. This robot uses dual-layer dry adhesives to climb smooth, vertical surfaces. Because dry adhesives are passive and stick to various surfaces, they have advantages over mechanisms such as suction, claws and magnets. The mechanical design and posture of Abigaille-III were optimized to reduce pitchback forces during vertical climbing. The robot’s electronics were designed around a Field Programmable Gate Array, producing a versatile computing architecture. The robot was reconfigured for vertical climbing with both 5 and 6 legs, and with 3 or 4 motors per leg, without changes to the electronic hardware. Abigaille-III demonstrated dexterity through vertical climbing on uneven surfaces, and by transferring between horizontal and vertical sur-faces. In endurance tests, Abigaille-III completed nearly 4 hours of continuous climbing and over 7 hours of loitering, showing that dry adhesive climbing systems can be used for extended missions.

Developing efficient walking gaits for quadruped robots has intrigued investigators for years. Trot gait, as a fast locomotion gait, has been widely used in robot control. This paper follows the idea of the six determinants of gait and designs a trot gait for a parallel-leg quadruped robot, Baby Elephant. The walking period and step length are set as constants to maintain a relatively fast speed while changing different foot trajectories to test walking quality. Experiments show that kicking leg back improves body stability. Then, a steady and smooth trot gait is designed. Furthermore, inspired by Central Pattern Generators (CPG), a series CPG model is proposed to achieve robust and dynamic trot gait. It is generally believed that CPG is capable of producing rhythmic movements, such as swimming, walking, and flying, even when isolated from brain and sensory inputs. The proposed CPG model, inspired by the series concept, can automatically learn the previous well-designed trot gait and reproduce it, and has the ability to change its walking frequency online as well. Experiments are done in real world to verify this method.

Biological inspiration has spawned a wealth of solutions to both mechanical design and control schemes in the efforts to develop agile legged machines. This paper presents a compliant leg mechanism for a small six-legged robot, HITCR-II, based on abstracted anatomy from insect legs. Kinematic structure, relative proportion of leg segment lengths and actuation system were analyzed in consideration of anatomical structure as well as muscle system of insect legs and desired mobility. A spring based passive compliance mechanism inspired by musculoskeletal structures of biological systems was integrated into distal segment of the leg to soften foot impact on touchdown. In addition, an efficient locomotion planner capable of generating natural movements for the legs during swing phase was proposed. The problem of leg swing was formulated as an optimal control procedure that satisfies a series of locomotion task terms while minimizing a biologically-based objective function, which was solved by a Gauss Pseudospectral Method (GPM) based numerical technique. We applied this swing generation algorithm to both a simulation platform and a robot prototype. Results show that the proposed leg structure and swing planner are able to successfully perform effective swing movements on rugged terrains.

Unlike birds, insects lack control surfaces at the tail and hence most insects modify their wing kinematics to produce control forces or moments while flapping their wings. Change of the flapping angle range is one of the ways to modify wing kinematics, resulting in relocation of the mean Aerodynamic force Center (mean AC) and finally creating control moments. In an attempt to mimic this feature, we developed a flapping-wing system that generates a desired pitching moment during flap-ping-wing motion. The system comprises a flapping mechanism that creates a large and symmetric flapping motion in a pair of wings, a flapping angle change mechanism that modifies the flapping angle range, artificial wings, and a power source. From the measured wing kinematics, we have found that the flapping-wing system can properly modify the flapping angle ranges. The measured pitching moments show that the flapping-wing system generates a pitching moment in a desired direction by shifting the flapping angle range. We also demonstrated that the system can in practice change the longitudinal attitude by generating a nonzero pitching moment.

The fluid dynamics of flapping insect wing in ground effect is investigated numerically in this study. To model the insect wing cross-section in forward-flight mode, the laminar flow over a NACA0012 airfoil animated by a combination of harmonic plunge and pitch rotation is considered. To implement the simulation, the proposed immersed boundary-lattice Boltzmann method is employed. By fixing the Reynolds number and the amplitude of motion, we systematically examine the influences of the distance between the foil and the ground and the flapping frequency on the flow behaviors. As compared to the situation out of ground effect, the forces for foil placed in close proximity to the ground show some differences. The mean drag coefficient is increased at low frequency and decreased at high frequency. Meanwhile, the mean lift coefficient is increased at both low and high frequencies and decreased at middle frequency. Moreover, an interesting phenomenon with oblate vortices due to vortex interaction with the ground is observed.

In recent decades, the take-off mechanisms of flying animals have received much attention in insect flight initiation. Most of previous works have focused on the jumping mechanism, which is the most common take-off mechanism found in flying animals. Here, we presented that the rhinoceros beetle, Trypoxylus dichotomus, takes off without jumping. In this study, we used   3-Dimensional (3D) high-speed video techniques to quantitatively analyze the wings and body kinematics during the initiation periods of flight. The details of the flapping angle, angle of attack of the wings and the roll, pitch and yaw angles of the body were investigated to understand the mechanism of take-off in T. dichotomus. The beetle took off gradually with a small velocity and small acceleration. The body kinematic analyses showed that the beetle exhibited stable take-off. To generate high lift force, the beetle modulated its hind wing to control the angle of attack; the angle of attack was large during the upstroke and small during the downstroke. The legs of beetle did not contract and strongly release like other insects. The hind wing could be con-sidered as a main source of lift for heavy beetle.

A bioinspired trajectory generation approach for Unmanned Aerial System (UAS) rapid Point-to-Point (PTP) movement was presented. The approach was based on general tau theory developed by biologists from observing and studying the behavior of birds and some other animals. We applied the bioinspired approach to the rapid PTP movement problem of a rotary UAS and derived two different trajectory planning strategies, namely, the tau coupling strategy and the intrinsic tau gravity guidance strategy. Based on general tau theory, according to the dynamic model of UAS, we presented a new strategy named intrinsic tau jerk guidance which can fit the movement that the initial acceleration of the UAS is zero. With new strategies, flight trajectory generation examples with a UAS were presented. The kinematics and dynamics analyses of the UAS for rapid PTP movement were presented with simulation results which show that the generated trajectories were feasible.

This paper presents a novel robotic sensor system that can monitor volatile chemicals and airflow. The system is modelled on characteristics of the human body that are thought to have a significant influence on the human odour and airflow senses. In particular, the effect of buoyant airflow due to body heat acts to gather volatile chemicals over large areas of the human body and carry them to the nose. It is postulated that this effect increases the receptive area for human olfaction. In addition, the interaction between rising air heated by the body and external airflow produces a temperature distribution about head height that can be used to infer airflow direction and magnitude. A heated sensor system was constructed to investigate these effects and the resulting sensor was mounted on a mobile robot. The design of the sensor system is described. Results are presented which demonstrate its ability to measure airflow direction and detect chemical signals over a wider receptive field compared with an unheated sensor.

We proposed a kind of bionic leaf to simulate the thermal effect of leaf transpiration. The bionic leaf was firstly designed to be composed of a green coating, a water holding layer, a Composite Adsorbent (CS) layer and an adsorption-desorption rate controlling layer. A thermophysical model was established for the bionic leaf, and the dynamic simulation results reveal that the water holding layer is not necessary; a CS of high thermal conductivity should be selected as the CS layer; the adsorp-tion-desorption rate controlling layer could be removed due to the low adsorption-desorption rate of the CS; and when CaCl2 mass fraction of the CS reaches 40%; the bionic leaf could simulate the dynamic thermal behavior of the natural leaf. Based on the simulation results, we prepared bionic leaves with different CaCl2 content. The thermographies of the bionic leaf and the natural leaf were shot using the Infrared Thermal Imager. The measured average radiative temperature difference between the bionic and natural leaves is less than 1.0 ?C.

To achieve favorable Frictional Tactile Sensation (FTS) for robot and humanoid fingers, this report investigated the effects of human finger sweat on Friction Coefficient (FC) and verified the effectiveness of artificial sweat on FTS for a humanoid finger. The results show that the model sweat (salt and urea water faked real sweat) increases the FC of the real finger sliding on the high hygroscopic and rough surface (paper), whereas on the low hygroscopic and smooth surface (PMMA), the sweat forms a fluid film and decreases FC, restricting severe finger adhesion. Further, the film formation and capillary adhesion force of sweat were discussed. The experimental results with the artificial sweats (ethanol and water) and humanoid finger (silicone rubber skin with tactile sensors) verifies the effectiveness. The artificial sweat restricts severe adhesion (stick-slip vibration), and enhances cognitive capability of FTS.

Microfluidic networks are extensively used in miniaturized lab-on-a-chip systems. However, most of the existing micro-channels are simply designed and the corresponding microfluidic systems commonly require external pumps to achieve effec-tive fluid transport. Here we employed microfabrication techniques to replicate naturally-optimized leaf venations into synthetic hydrogels for the fabrication of pumpless microfluidic chips. The unique properties of leaf-inspired microfluidic network in convectively transporting fluid were characterized at different inclination angles. Flow velocity inside these microfluidic net-works was quantitatively measured with Particle Image Velocimetry (PIV). Mass diffusion from biomimetic microfluidic network to surrounding bulk hydrogels was investigated. The results demonstrate that the leaf-inspired microfluidic network can not only effectively transport fluid without the use of external pumps, but also facilitate rapid mass diffusion within bulk hy-drogel chips. These leaf-inspired microfluidic networks could be potentially used to engineer complex pumpless or-gan-on-a-chip systems.

Zein/HA fibrous membranes were successfully prepared by electrospinning the zein/HA solution mixed by magnetic stirrer (Method I) or ultrasonic power (Method II). The morphology of zein/HA nanocomposite fibers and the distribution of HA within the fibers electrospun by two methods were researched by Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). In Method I, the distribution of HA nanoparticles is not homogeneous and HA particles tend to agglom-erate. The relatively homogeneous HA distribution can be observed in the membranes electrospun by Method II. Using mag-netic stirrer to prepare the electrospinning solution improves the wettability of zein/HA membranes. From the viewpoint of application, electrospun zein/HA membranes fabricated by the solution mixed via Methods I and II both possessed reasonable tensile strength and elongation at break for both handling and sterilization. Considering two aspects of strength and elongation, electrospun zein/HA membranes fabricated by Method I are more balanced than those fabricated by Method II. Biological performances of the control zein and zein/HA membranes were assessed by in vitro culture of hMSCs. Results show that both types of the membranes can support cell proliferation. The cells cultured on the zein/HA membranes electrospun by Method I with 5 wt% HA (on weight of zein) show significantly higher proliferation than those cultured on the control zein membranes on the seventh day. The electrospun zein/HA fibrous membranes show promises for bone tissue engineering applications.

The purpose of this study is to explore and develop a novel biocompatibility drug delivery carrier for controllingontrolled drug release. The α-eleostearic acid grafted hydroxyapatite (α-ESA-g-HA) composite was synthesized by using silane coupling agent and characterized by Fourier Transformation Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscope (SEM), respectively. The in vitro drug loading and controlled release behaviors of α-ESA-g-HA composite were investigated using ciprofloxacin as the model drug. The amount of ciprofloxacin loading and released was cal-culated by absorbance value which was determined by UV-Vis spectrophotometry at wavelength of 277 nm. The biocompatibility of α-ESA-g-HA composite was assessed by 3-(4,5)-dimethylthiahiazo(-z-yl)-3,5-di-phenytetrazoliumromide(MTT) assay, nuclear morphology and platelet adhesion. The results showed that the α-ESA-g-HA had nontoxic and good biocompatibility. According to the results mentioned above, the α-ESA-g-HA is an effective drug delivery carrier, which could increase drug loading capacity and control drug release, so further studies are necessary to evaluate clinical application and human health care.

We investigated an integrated manufacturing method to develop lightweight composite materials. To design the preparation process for the integrated honeycomb plates, the shear and compressive mechanical properties of the corresponding composite materials were also investigated. The results indicate that these composite materials, with two types of resins reinforced by short basalt fibers, exhibit obvious toughness, particularly in their compressive properties. The Epoxy Resin (ER) is denser and has better bonding at the fiber and matrix interface than the vinyl ester resin matrix. Therefore, the ER exhibits better shear and compressive strengths than the vinyl ester resin matrix, thereby providing a design technology of the preparation process of the integrated honeycomb plate. The matrix material of this plate is composed of an epoxy (E51), a curing agent (593), and a thinner (501) at a ratio of 10:3:1; short basalt fibers are added as a reinforcing material at a 30% volume fraction. By increasing the curing temperature and other experimental conditions, we obtained an expected integrated honeycomb plate. This integrated honeycomb plate possesses properties such as a high fiber content, good shear and compressive performance, and high proc-essing efficiency.

This study details an investigation of the viscoelastic behavior of some biomaterials (nacre, cattle horn and beetle cuticle) at lamellar length scales using quasi-static and dynamic nanoindentation techniques in the materials’ Transverse Direction (TD) and Longitudinal Direction (LD). Our results show that nacre exhibits high fracture toughness moving towards a larger cam-paniform as the stress frequency varies from 10 Hz to 200 Hz. Elytra cuticle exhibits the least fracture toughness presenting little energy dissipation in TD. It was initially speculated that the fracture toughness of the subject materials would be directly related to energy-dissipating mechanisms (mechanical hysteresis), but not the maximum value of the loss tangent tanδ. However, it was found that the materials’ elastic modulus and hardness are similar in both the TD and LD when assessed using the quasi-static nanoindentation method, but not dynamic nanoindentation. It is believed that the reported results can be useful in the design of new crack arrest and damping materials based on biological counterparts.

Electronic systems are vulnerable in electromagnetic interference environment. Although many solutions are adopted to solve this problem, for example shielding, filtering and grounding, noise is still introduced into the circuit inevitably. What impresses us is the biological nervous system with a vital property of robustness in noisy environment. Some mechanisms, such as neuron population coding, degeneracy and parallel distributed processing, are believed to partly explain how the nervous system counters the noise and component failure. This paper proposes a novel concept of bio-inspired electromagnetic protec-tion making reference to the characteristic of neural information processing. A bionic model is presented here to mimic neuron populations to transform the input signal into neural pulse signal. In the proposed model, neuron provides a dynamic feedback to the adjacent one according to the concept of synaptic plasticity. A simple neural circuitry is designed to verify the rationality of the bio-inspired model for electromagnetic protection. The experiment results display that bio-inspired electromagnetic pro-tection model has more power to counter the interference and component failure.