Research into evaporating droplets on patterned surfaces has grown exponentially, since the capacity to control droplet morphology has proven to have significant technological utility in emerging areas of fundamental research and industrial applications. Here, we incorporate two interest domains — complex wetting patterns of droplets on structured surfaces and the ubiquitous coffee-ring phenomenon

In the present study, we investigated the evaporation process and deposition pattern of saline droplet on a copper substrate with different roughness under 40 °C ambient temperature. These four substrates are classified as smooth surface and rough surface based on their droplet contact angles. It has been found in this study that the evaporation pattern of droplets has a strong relationship to substrate

Super-hydrophobic surfaces are quite common in nature, inspiring people to continually explore its water-repellence property and applications to our lives. It has been generally agreed that the property of super-hydrophobicity is mainly contributed by the microscale or nanoscale (or even smaller) architecture on the surface. Besides, there is an energy barrier between the Cassie-Baxter wetting state

Gradient wettability is important for some living organisms. Herein, the dynamic responses of water droplets impacting on the surfaces of four regions along the wing vein of cicada Cryptotympana atrata fabricius are investigated. It is revealed that a gradient wetting behavior from hydrophilicity (the Wenzel state) to hydrophobicity and further to superhydrophobicity (the Cassie-Baxter state) appears

At present, biomimetic antifouling research objects are mostly concentrated on the fast-moving marine organism, but the anti-fouling effect of the low-speed or static marine equipment is not obvious. This paper describes the anti-fouling mechanism of soft coral (Sarcophyton trocheliophorum), including the physical defense mechanism and the bactericidal ability of mucus and coral powder. As a sessile

Collagen is one of the most versatile tissues of living organisms that comes in many shapes and sizes, providing functions ranging from tissue matrix through, ligament formation up to enabling mineralization in teeth. The detailed light microscopy and Scanning Electron Microscopy (SEM) observations conducted in this study, allowed us to investigate morphology, sizes and crimp patterns of collagen fibers

The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation. Here we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet mobility. Three biomimetic strategies are included, (i) reducing the liquid-solid interfacial area

The ability to grip unhatched eggs is a skill exploited by the ants Harpegnathos venator, as they care their brood in tunneled nests, which is of extreme difficulty to keep the eggs intact while gripping. In this paper we propose a mathematical modeling method to elucidate the mechanism of such a gripping behavior in the ant mandibles. The new method can be subdivided into following steps. As a preliminary

Redundancy facilitates some of the most remarkable capabilities of humans, and is therefore omni-present in our physiology. The relationship between redundancy in robotics and biology is investigated in detail on the Series Elastic Dual-Motor Actuator (SEDMA), an actuator inspired by the kinematic redundancy exhibited by myofibrils. The actuator consists of two motors coupled to a single spring at

To improve the controllability for the evaporation process of fuel spray impinging on the cylinder wall, an experimental study on the development of morphological process of different fuel droplets on aluminium alloy surfaces is carried out. The metal surfaces with different wettability are prepared by laser etching and chemical etching for the experiments. In total, three different fuels are tested

Evaporation of multicomponent droplets has gained much attention nowadays because of their complex flow fields and various deposition patterns. Here we observe strong flows in evaporating sodium chloride saline droplets with suspended alumina oxide nanoparticles. The evolution of flow pattern was studied by tracking the trajectories of particles and the velocity field was investigated with Particle

Most commercial spine analogues are not intended for biomechanical testing, and those developed for this purpose are expensive and yet still fail to replicate the mechanical performance of biological specimens. Patient-specific analogues that address these limitations and avoid the ethical restrictions surrounding the use of human cadavers are therefore required. We present a method for the production

Although the toughening of Calcium phosphate (CaP) scaffold by the addition of fiber has been well recognized, integrated mechanical, structural and functional considerations have been neglected in the design and fabrication of CaP scaffold implant. The emerging 3D printing provides a promising technique to construct CaP scaffold with precise size and elaborate microstructure. However, the most challenge

Most commercially available spine analogues are not intended for biomechanical testing, and the few that are suitable for using in conjunction with implants and devices to allow a hands-on practice on operative procedures are very expensive and still none of these offers patient-specific analogues that can be accessed within reasonable time and price range. Man-made spine analogues would also avoid

The Leading-Edge (LE) serrations on owls’ wings are known to be responsible for silent flight. However, this design has rarely been applied to reduce the noise of rotational rotor propellers and the morphologies of the existing serration designs are diverse. Here, we present a comparative study of LE serrations with different morphologies in terms of the effectiveness in suppressing noise and promoting

Applying hot-embossing technology, a simple and cost-effective method for the fabrication of microstructured High Density Polyethylene (HDPE) surfaces with a robust superhydrophobic wetting state is proposed. Micro-meshes and micro-grooves in the flexible template are filled by the PE melt in the hot embossing process. Subsequently, a two-stage microstructure on the PE film surface is formed. This

Wettability is known to play a major role in enhancing pool boiling heat transfer. In this context bioinspired surfaces can bring significant advantages in pool boiling applications. This work addresses a numerical investigation of bubble growth and detachment on a biphilic surface pattern, namely in a superhydrophobic region surrounded by a hydrophilic region. Surface characteristics resemble bio-inspired

Bionic inspiration from human thumb and index finger was the drive to design a high-performance two-finger dexterous hand. The size of each phalanx and the motion range of each joint in the human thumb and index finger were summarized, and the features of three grasping patterns were described in detail. Subsequently, a two-finger dexterous bionic hand with 6 Degrees of Freedom (DoFs) was developed

The application of trenchless technology is the trend of underground public facilities’ installation, replacement and repairing. As the soil-engaging component during penetrating bore, the working resistance of penetration head has remarkable effect on energy consumption of the whole working process. Some typical soil-digging animals, like pangolin and earthworm, they own special micro structures on

The attitude control system of a flapping-wing flying robot plays an important role in the precise orientation and tracking of the robot. In this paper, the modeling of a bird-like micro flapping-wing system is introduced, and the design of a sliding mode controller based on an Extended State Observer (ESO) is described. The main design difficulties are the control law and the adaptive law for the

The aerodynamic noise generated by the centrifugal fan used in the air conditioner is related to the comfort of human living and working, which can be controlled by using the bionic design and optimization of key components of centrifugal fan. Inspired by the non-smooth leading edge of long-eared owl wing, eight kinds of volute tongues are proposed to reduce the aerodynamic noise of a centrifugal fan

This paper simulates the cuckoo incubation process and flight path to optimize the Wavelet Neural Network (WNN) model, and proposes a parking prediction algorithm based on WNN and improved Cuckoo Search (CS) algorithm. First, the initialization parameters are provided to optimize the WNN using the improved CS. The traditional CS algorithm adopts the strategy of overall update and evaluation, but does

Wet adhesion is widely adopted in biological adhesion systems in nature, and it is beneficial to design new materials with desired properties based on the underlying physics of wet adhesion. The aim of this work is to develop a design criterion to regulate the wet adhesion. The effects of different contact shapes (flat and sphere) and morphologies of the substrate (smooth, microstructure and nanostructure)

The effects of hybrid porous-serrated trailing edge on flow structure and sound source of NACA65(12)-10 at moderate Reynolds number (Rec = 5 × 105) have been investigated by Delayed Detached Eddy Simulation (DDES). Compared with conventional serrated trailing edge, the pressure fluctuation in the vicinity of hybrid porous-serrated trailing edge is further decreased significantly. The typical necklace

Scientists have long looked to nature and biology in order to understand and model solutions for complex real-world problems. The study of bionics bridges the functions, biological structures and functions and organizational principles found in nature with our modern technologies, numerous mathematical and metaheuristic algorithms have been developed along with the knowledge transferring process from

When humans jump down from a high position, there is a risk of serious injury to the lower limbs. However, cats can jump down from the same heights without any injury because of their excellent ability to attenuate impact forces. The present study aims to investigate the macro/micro biomechanical features of paw pads and limb bones of cats, and the coordination control of joints during landing, providing

Research on antistatic superhydrophobic surfaces has attracted widespread attention in some fields. However, in the application of superhydrophobic materials, fabricating stable and practical superhydrophobic surfaces through facile and low-cost approaches still faces considerable challenges. Herein, a polyphenylene sulfide (PPS)-based antistatic superhydrophobic composite coating with a high water

This paper introduces the design and fabrication of a smart and Hybrid Composite Finger (HCF) to achieve finger-like motions, such as holding and tapping motions. Bionic research on tapping motion of the index finger was conducted to obtain its structural and tapping parameters. The HCF, actuated by Shape Memory Alloy (SMA) wires, possesses a hybrid structure which is composed of a rigid structure

Foothold identification is a key ability for legged robots that allows generating terrain adaptive behaviors (e.g., gait and control parameters) and thereby improving mobility in complex environment. To this end, this paper addresses the issue of foothold characterization and identification over rugged terrain, from the terrain geometry point of view. For a terrain region that might be a potential

It is generally known that forelimbs and hindlimbs play different roles during locomotion, but the possible differences in the biomechanical functions of the metacarpal pad and metatarsal pad remain unknown. This study combined kinematic and pressure data from dogs to investigate the key roles of the metacarpal and metatarsal pads. The peak vertical ground reaction force of the metacarpal pad was found

Tissue engineered skeletal muscle is expected to treat muscle defects caused by trauma and disease. However, designing and manufacturing thick and complex tissue engineered skeletal muscle requires vascularization to ensure its internal cell viability and nutrient supply in vitro. In this article, we developed a set of Direct-Writing (DW) bio-printing procedure to manufacture a prevascularized composite

Drosophila melanogaster, a.k.a. the common fruit fly, is a simple organism that may give a rapid, high-throughput response in regard to the therapeutic efficacy of nanoparticles and drugs, while circumventing the high environmental and monetary cost of today’s typical in vivo assays involving more complex animals, along with the immeasurable suffering imposed onto them. Here we give the progress report

Wettability plays a vital role in fundamental researches and practical applications. Wettability control and patterning have been widely studied in various fields. Although researches have grown rapidly, the methods are still restricted by limitations including complicated processes, high equipment requirements and shortage of methods to treat complex surfaces. Here we report a simple, low cost, array-based

Wall-climbing robots can work on steep terrain and obtain environment information in three dimensions for human in real time, which can improve operation efficiency. However, traditional single-mode robots cannot ensure the stable attachment on complex wall surfaces. Inspired by the structure characteristics of flies and clingfishes, three bionic structures including the flexible spine wheel, the adhesive

As a bionic therapy, hand-foot crawling has been reported to be used for the rehabilitation of low back pain. However, there have been few relevant biomechanical studies about this type of exercise. The purpose of this study was to calculate muscle activation and lumbar spinal load based on the examined limb kinematics and kinetics, which associated with hand-foot crawling at the different Centre of

Discoveries in geckos locomotion have advanced the bio-inspired robotics. However, the gecko-inspired robots still lag behind animals in attachments and maneuvers due to our failure to understand and implement gecko bionics thoroughly. Here, we studied the toe deployments that facilitate the upside-down motion of geckos by focusing on the directions and contact area of toes to offer inspirations for

The ability of natural living organisms, transferring deformations into locomotion, has attracted researchers’ increasing attention in building bionic actuators and smart systems. As a typical category of functional materials, magnetoresponsive composite elastomers, comprised of flexible elastomer matrices and rigid magnetic particles, have been playing critical roles in this field of research due

In this paper, the effect of stereom structure on the mechanical behavior of the Sea Urchin Inorganic Skeleton (SUIS) has been studied. The stereom microstructure of both Anthocidaris crassispina and Tripnenstes gratilla was characterized by Scanning Electron Microscopy (SEM). Results indicate that a three-layer porous structure consisting of a growth, a support, and a resorption (GSR) layer is a common

Anthropomorphic hands have received increasing research interest in the fields of robotics and prosthetics. But it is not yet clear how to evaluate their anthropomorphism. Similarity in the kinematic chain is essential to achieve both functionality and cosmesis. A few previous works have addressed the definition of anthropomorphism indexes, although they have some limitations in its definition. In

Aerial transportation and manipulation have attracted increasing attention in the unmanned aerial vehicle field, and visual servoing methodology is widely used to achieve the autonomous aerial grasping of a target object. However, the existing marker-based solutions pose a challenge to the practical application of target grasping owing to the difficulty in attaching markers on targets. To address this

The Synthetic Jet (SJ) control on the propulsion behavior of a foil in plunge-pitch motion is examined in this work by numerical simulations. An elliptic foil with ratio of 8 performs the plunge and pitch motions synchronously. A pair of SJs with the same frequency and strength is integrated into the upper and lower surfaces of the foil. As a result, the local flow field around the foil could be obviously

Following the contemporary research trend of exploring the potential of eco-friendly natural fibres, this work studies the effects of alkali and silane treatments, with varying concentrations, on the mechanical characterization of composites reinforced with kenaf and pineapple leaf fibre (PALF). Kenaf- and PALF-based composites were fabricated through the heat compression method. Their mechanical characterization

In this work, bio-inspired concepts, including a Self-Healing (SH) and super hydrophobic structure, were used to produce slow-release of urea fertilizer. Following a bottom-up process, an SH layer on the urea granule was produced from a combination of two natural waxes, palm and carnauba, and fabricated by a hot-melt coating process in a pan coater. Another layer for super hydrophobicity was formed

Ionic Polymer Metal Composite (IPMC) is a novel electrically actuated intelligent material with the advantages of big bending displacement, low driving voltage, flexible and so on. It has been recognized as one of the most attractive actuators with prospective applications for underwater robots and bionic organs. In this work, a capsule-like robot was introduced with the pectoral and caudal fins made

Emulating periodic main wing movement of a bird for generating lift and thrust remains a significant challenge in developing a robotic bird. The sequences of main wing motion are comprised of flapping, folding, bending, and twisting. In this paper, we concentrate on the flapping and folding motion, and design two wing mechanisms based on a 4-bar linkage structure: one is only for Flapping Motion (FM)

Solar power, as one of renewable energy, holds potential application for producing steam which relies on high-temperature liquid by traditional methods. Herein, steam was generated by a bio-inspired strategy derived from the plants transpiration using a Printed Recyclable Carbon Membrane (PRCM). The membrane structure facilitated the concentration of carbon particles for the photoreaction and the heat

This innovative work presents mechanical, physical and chemical characterization and analysis of newly extracted fiber from naturally resourced plant stem, named Spinifex littoreus fibers (SLF). This is a novel natural, biodegradable and sustainable reinforcement for an improved composite. Initially, the chemical constituents of SLF, such as cellulose, lignin, moisture and wax content were studied

Tuna, known for high endurance cruising, have already inspired several underwater robots and swimming studies. This study uses a biomimetic robotic tuna to investigate how different caudal fin planform geometries affect the thrust production and flow structures during Body and/or Caudal Fin (BCF) swimming. The robot was tethered to a circulating water tunnel, and swimming was simulated by moving water

The morphology of bone repair materials, such as particle size and roughness of the materials surface, can affect the adsorption of protein molecules. The effects of surface morphology on the absorption of proteins with different charges were studied. Submicron and nano hydroxyapatite (HA) powders prepared by the chemical precipitation method were coated on the surface of a gold sheet by electrophoretic

Energy efficiency has been the focus of quadruped robot research. Decreasing the energy loss caused by the DC motor can contribute to the walking efficiency of electrically actuated quadruped robots. Most works have focused on the quadruped mechanisms or actuations such as the Series Elastic Actuation (SEA). This work proposes a better efficient controller to perform the stable 5 m·s−1 movements of

Fish commonly execute rapid linear accelerations initiated during steady swimming, yet the function of the median fins during this process is less understood. We find that the erection/folding time (from the starting time of the linear acceleration (0 s) to the starting time of the folding movement of the fin), as well as the spreading area of the median fins, actively change during the linear acceleration

Fugitive dust has been recognized as an important contributor to air pollution, and artificial porous fence is one of the most effective management strategies to reduce fugitive dust in open areas. To improve the shelter effects and efficiency of Particulate Matter (PM) reduction of traditional fences, this study proposed five bionic fences and their capability was evaluated through wind tunnel tests

In modern mechanical design, non-sticky and non-slippery surfaces are highly preferred in many applications. In this work, bio-inspired micro patterns of hexagonal pillar and round dimple with various geometric parameters are fabricated, and the static friction and adhesion performances of the prepared surfaces are investigated. It is found that hexagonal pillar patterns can enhance the static friction

This paper presents a frog-inspired swimming robot based on articulated pneumatic soft actuator. To realize the miniaturization of the robot and enhance its environmental adaptability, combined with the advantages and characteristics of soft materials, an articulated pneumatic soft actuator is designed based on analysis of a frog’s propulsion characteristics. A structural model is established to analyse

Higher strength and lower degradation rate of Fe compared to magnesium and zinc have made it the most reliable for orthopaedic reconstruction. Hence, this paper studies the morphological and mechanical characteristics of porous Fe fabricated using subtractive manufacturing for load bearing bone replacement. Three types of porous Fe (19%, 39% and 59%) were prepared and then modelled into a 3D model

A flexible Artificial Lateral Line (ALL) sensor is presented in this paper, featuring a barium titanate/polyvinylidene fluoride-trifluoroethylene [BTO/P(VDF-TrFE)] nanofiber mat, a hydrogel cupula, and a constriction structure in the canal.. The excellent piezoelectric performance of the BTO/P(VDF-TrFE) nanofiber, superior to that of a pristine P(VDF-TrFE) nanofiber, helps improve the sensitivity of

This paper reports the effect of the Center of Gravity (CG) position on lateral flight dynamic stability of hovering KUBeetle, a tailless FW-MAV, providing further insights on the effects of asymmetries in body mass distribution and wing kinematics. For the current study, the standard linearized equations of motion were applied as in the previous work on longitudinal dynamic stability. The stability

A foot positioning compensator is developed in this paper for a full-body humanoid to retrieve its balance during continuous walking. An online Foot Position Compensator (FPC) is designed to improve the robustness of biped walking, which can modify predefined step position and step duration online with sensory feedback. Foot placement parameters are learned by the FPC based on the Policy Gradient Reinforcement

Improving the strength of bone cement is one of the critical goals in cement designing to maintain their integrity and stabilize connection between the cement and their surrounding tissue during the time that the cement has been replaced by matured bone tissue. To this aim, the authors decided to evaluate setting behavior and compressive strength of Magnesium Phosphate Cement (MPC) by adding car-boxylated

Abstract Areca catechu, is a species of palm belonging to the family of Arecaceae/Palmae, grows vertically, to the height of 10 m to 20 m, the stem is straight, solitary and slender, 10 cm to 15 cm in diameter, with marks of annulated scars of fallen leaf sheaths. Areca fibres are predominantly extracted not only from the fruit as areca husk, but also from leaf stalks and fronds. In this review paper