Bionic Surface Research Articles

Numerical research on the effect of leaf venation shape bionic surface extension and the location on latent heat storage system

The charging process of solar power applied leaf venation shape bionic latent heat thermal energy storage (LHTES) system was studied in the present research. n-Eicosane was chosen for the phase change materials (PCMs) and the enthalpy porosity method and Boussinesq approximation were applied. A series of transient three-dimensional models built by structure mesh were established to calculate the LHTES charging process. The leaf venation shape bionic surface extension was settled at five different locations to match the effect of natural convection caused by material expansion in the melting process. Parameters of the average temperature, melting fraction, velocity magnitude, and the ratio of latent heat for total energy absorbed were analyzed. The result indicated that the leaf venation shape bionic structure extension and its position on the Z axis have a large impact on the X, Y, Z direction heat diffusion, and the best distance to improve thermal consistency was speculated to be at between 1 and 2 mm from bottom.

Modified superhydrophilic/underwater superoleophobic mullite fiber-based porous ceramic for oil-water separation

This work proposed a new strategy for preparing a superhydrophilic/underwater superoleophobic material based on mullite fiber-based porous ceramic as the matrix and polyethylenepolyamine (PEPA) with high surface energy as the coating material. The PEPA-DA (PDA) coating used as the superhydrophilic/underwater superoleophobic membrane was fabricated via the bionic surface grafting technology. Dopamine (DA) was used as a binder to graft PEPA onto the surface and into the pores of the matrix material to in situ form a PDA coating that has a multi-level structure. The prepared mullite ceramic/PDA coating could be used to separate oil/water mixtures with short separation time and high efficiency. Consequently, the mullite fiber-based porous ceramic was considered to be a novel substitutional matrix material for preparing the super-wetting membrane.

Vascular cell behavior on heparin-like polymers modified silicone surfaces: The prominent role of the lotus leaf-like topography

Vascular cell behavior on material surfaces, such as heparin-like polymers, can be affected by the surface chemical composition and surface topological structure. In this study, the effects of heparin-like polymers and lotus leaf-like topography on surface vascular cell behavior are considered. By combining multicomponent thermo-curing and replica molding, a polydimethylsiloxane surface containing bromine (PDMS-Br) with lotus leaf-like topography is obtained. Heparin-like polymers with different chemical compositions are grafted onto PDMS-Br surfaces using visible-light-induced graft polymerization. Compared with unmodified PDMS-Br, surfaces modified by sulfonate-containing polymers are more friendly to vascular cells, while those modified by a glyco-polymer are much more resistant to vascular cells. The introduction of lotus leaf-like topography results in different degrees of decrease in cell density on different heparin-like polymer-modified surfaces. In addition, the combination of heparin-like polymers and lotus leaf-like topography results in the change in protein adsorption, indicating that the two factors may affect the surface vascular cell behavior by affecting the adsorption of relative proteins. The combination of bionic surface topography and different chemical components of heparin-like polymers on material surfaces suggests a new way of engineering cell-material interactions.

Experimental study on the influence of bionic channel structure on waste heat utilization equipment

AbstractIn this paper, in order to improve the efficiency of waste heat utilization, based on the movement type and shape of the snake, snake bionic surfaces with different structures were designed, and CuO–H2O nanofluids were used instead of traditional working fluids, and they were coupled together and applied to waste heat utilization equipment. The main work is to experimentally study the effects of nanofluids mass fraction (w = 0.1 wt%, 0.3 wt%, 0.5 wt%), amplitude of bionic channel structure (A = 1 mm, A = 2 mm, A = 3 mm), angular frequency of bionic channel structure (ω = 20 rad/s, ω = 25 rad/s, ω = 30 rad/s), phase shift of bionic channel structure (α = 0°, 90°, 180°), and Reynolds number (Re = 1,300–1800) on the flow and heat transfer characteristics of working fluid. It was found that the heat transfer capacity of nanofluids increases with nanofluids mass fraction, angular frequency, amplitude and phase shift. Finally, the comprehensive performance of the whole experimental system was studied, and it was found that the greater the angular frequency, amplitude and phase shift, the better the comprehensive performance of the heat exchanger.

Ultradense Erythrocyte Bionic Layer Used to Capture Circulating Tumor Cells and Plasma-Assisted High-Purity Release.

The isolation and detection of rare circulating tumor cells (CTCs) from patient peripheral blood can help early diagnosis of cancer and evaluation of therapeutic outcomes. At present, most of the available strategies for enriching CTCs face serious problems with purity due to the nonspecific interactions between the capture medium and leukocytes. Inspired by the immune evasion ability of homologous red blood cells (RBCs), we modified the tumor-targeting molecule folic acid (FA) on the surface of RBCs by hydrophobic interactions. Under the treatment of polybrene, the charges on the surface of RBCs are neutralized, which reduces the mutual repulsion force. Furthermore, RBCs treated with polyethylene also have excellent deformability, thereby enabling engineered RBCs to form a dense bionic layer on the adhesive glass slide, which can greatly inhibit the nonspecific adhesion of leukocytes. The bionic layer can achieve high-purity enrichment of tumor cells in phosphate-buffered saline (PBS), and we can achieve high-activity release in plasma. The cell count showed over 80% capture efficiency and over 70% release rate, and the purity of CTCs obtained in the artificial blood sample after release was higher than 90%. The RBC bionic surface coating is notably cost-effective and highly applicable for CTC isolation in clinic practice, and thus provides new prospects for designing cell-material interfaces for advanced cell-based biomedical studies in the future.

Smart Bionic Surfaces with Switchable Wettability and Applications

In order to satisfy the needs of different applications and more complex intelligent devices, smart control of surface wettability will be necessary and desirable, which gradually become a hot spot and focus in the field of interface wetting. Herein, we review interfacial wetting states related to switchable wettability on superwettable materials, including several classical wetting models and liquid adhesive behaviors based on the surface of natural creatures with special wettability. This review mainly focuses on the recent developments of the smart surfaces with switchable wettability and the corresponding regulatory mechanisms under external stimuli, which is mainly governed by the transformation of surface chemical composition and geometrical structures. Among that, various external stimuli such as physical stimulation (temperature, light, electric, magnetic, mechanical stress), chemical stimulation (pH, ion, solvent) and dual or multi-triggered stimulation have been sought out to realize the regulation of surface wettability. Moreover, we also summarize the applications of smart surfaces in different fields, such as oil/water separation, programmable transportation, anti-biofouling, detection and delivery, smart soft robotic etc. Furthermore, current limitations and future perspective in the development of smart wetting surfaces are also given. This review aims to offer deep insights into the recent developments and responsive mechanisms in smart biomimetic surfaces with switchable wettability under external various stimuli, so as to provide a guidance for the design of smart surfaces and expand the scope of both fundamental research and practical applications.

Study on structure and process performance of laser cladding nickel-based coating

Abstract Thermal fatigue and wear are the main failure modes of metal parts, which are mostly found on the surface of the parts. Therefore, There is great significance for improving the service life of the parts on strengthening the surface of the parts. The biological surfaces are used as bionic model to design and laser prepare bionic surfaces with parallel structure, square structure and triangle structure. The bionic surface samples are studied on the thermal fatigue characteristics and wear resistance. Based on experimental research, the bionic structure is helpful to improve the thermal fatigue resistance and wear resistance comparing with the untreated specimen surface. Triangular structure is better than parallel structure and square structure. The amount of wear changes nonlinearly with time every bionic structure.

A Novel Stereocomplex Poly(lactic acid) with Shish-Kebab Crystals and Bionic Surface Structures as Bioimplant Materials for Tissue Engineering Applications.

The development of green material possessing with great mechanical properties and biocompatibility has become a primary goal for high-performance biological material applications. Herein, the oriented shish-kebab crystals of stereocomplex poly(lactic acid) (SC-PLA) are first reported to be successfully fabricated through a feasible solid-state drawing (SSD) process to simultaneously enhance the mechanical performance and biocompatibility. The resultant biomaterial exhibits a tensile strength of 373 MPa and elongation about 9%, with elastic modulus about 8.1 GPa. Such an outstanding toughening effect is due to an amalgamation of enhanced crystallinity of epitaxial secondary growth lamellae and orientation degree of the fibrous backbone of the SC-PLA samples, both gradually increasing with the draw ratio of SSD increasing. Uniquely distinguished from the typical biomedical polymer with the smooth surface structure, the as-obtained SC-PLA samples possess a surface morphology of parallel microgrooves within ridge structures, attributing to the highly oriented fibrous backbone structure complemented with regularly arranged epitaxial lamellas. This unique trait well represents the human vascular endothelial microstructure that is desirable for cell adhesion-growth to extend its proliferation, differentiation, and activity on the surface of SC-PLA.

Formation of bionic surface textures composed by micro-channels using nanosecond laser on Si3N4-based ceramics

Bionic surface textures exhibit excellent properties in improving the friction and wear resistance. To obtain the micro-channel bionic textures with high-quality on Si3N4/TiC ceramic surface, the effect of laser process parameters by using a nanosecond laser with 1064 nm wavelength on micro-channel surface quality and geometry is studied. The surface morphology, depth and width of the micro-channels are examined by scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). The surface compositions of heat-affected are detected by energy dispersive spectrometer (EDS). Results show that the surface morphology and geometry of the micro-channels are seriously influenced by the laser process parameters. Higher laser power, lower scanning speed, higher frequency and overscan are prone to produce larger channel depth and width due to more accumulated energies. The optimal laser process parameters of the micro-channels are obtained, correspondingly the micro-channel depth and width are about 40–45 μm and 55–60 μm, respectively; meanwhile, it is found that the oxidation occurs in the heat-affected zone. Finally, five kinds of bionic surface textures orderly composed by micro-channels (square, circle, diamond, hexagon and sector) are fabricated on Si3N4/TiC ceramic surface based on the optimal laser process parameters.

Thriving artificial underwater drag-reduction materials inspired from aquatic animals: progresses and challenges.

In the past decades, drag-reduction surfaces have attracted more and more attention due to their potentiality and wide applications in various fields such as traffic, energy transportation, agriculture, textile industry, and military. However, there are still some drag-reduction materials that need to be deeply explored. Fortunately, natural creatures always have the best properties after long-term evolution; aquatic organisms have diversified surface microstructures and drag-reducing materials, which provide design templates for the development of thriving artificial underwater drag-reduction materials. Aquatic animals are tamed by the current while fighting against the water, and thus have excellent drag reduction that is unparalleled in water. Inspired by biological principles, using aquatic animals as a bionic object to develop and reduce frictional resistance in fluids has attracted more attention in the past few years. More and more aquatic animals bring new inspiration for drag-reduction surfaces and a tremendous amount of research effort has been put into the study of surface drag-reduction, with an aim to seek the surface structure with the best drag-reduction effect and explore the drag-reduction mechanism. This present paper reviews the research on drag-reduction surfaces inspired by aquatic animals, including sharks, dolphins, and other aquatic animals. Aquatic animals as bionic objects are described in detail, with a discussion on the drag-reduction mechanism and drag-reduction effect to understand the development of underwater drag-reduction fully. In bionic manufacturing, the effective combination of various preparation methods is summarized. Moreover, bionic surfaces are briefly explained in terms of traffic, energy sources, sports, and agriculture. In the end, both existing problems in bionic research and future research prospects are proposed. This paper may provide a better and more comprehensive understanding of the current research status of aquatic animals-inspired drag reduction.

DEVELOPMENT OF ELEMENTS OF THE TECHNOLOGY OF CREATION OF THE BIONIC STRUCTURE OF PROTECTIVE CLOTHING MATERIAL AGAINST THE THERMAL EFFECTS OF UNDERWATER WELDING

The article is devoted to research and development of technology elements for designing and manufacturing a new polymer material based on heat-resistant silicone with a special surface structure in the form of an ordered relief matrix that simulates a bionic surface (“shark skin”), created on the basis of digital processing of bionic models, providing a barrier against thermally dangerous particles of underwater welding. In order to determine the stability of the developed material to the thermal effects of a short-term open flame, experimental tests were carried out, which made it possible to determine that the damage to the surface of the new silicone material is insignificant. It does not lead to the destruction of the overall thickness of the protective material and further risks for the internal foam heat-protective layer of wetsuits – damage to the surface of the protrusions of the relief matrix (no more than 40 % of the initial parameters). The developed material allows one to increase the protection of the main surface of the clothing material.

Development of a novel hydrophobic and lipophilic material based on mullite fiber-based porous ceramics matrix used for highly efficient oil-water separation

The present work focused on developing a novel hydrophobic and lipophilic material for oil-water separation based on mullite fiber-based porous ceramics as the matrix material and octadecylamine (ODA) with low surface energy as the coating material. The bionic surface grafting technology was used to modify the porous ceramics, forming a multi-level structure used as the superhydrophobic membrane. The oil adsorption capacity, oil holding capacity and recyclability of the material for various oils were investigated. It was demonstrated that the modified ODA coating made the mullite fiber-based porous ceramics hydrophobic and lipophilic and could achieve fine effect of oil-water separation in a short time. The oil absorption performance was affected by the types of oil and the maximum adsorption capacity was generally more than 1 time of its own mass. Meanwhile, excellent oil holding capacity and recyclability were observed.

Optimization design and experimental analysis of bionic viscosity reduction of chisel type energy saving subsoiling shovel

In order to solve the problems of adhesion to soil and high resistance in traditional subsoiling shovel operation, a bionic energy-saving subsoiling shovel with bionic viscosity reducing and resistance reducing chisel is designed based on the polygon geometry structure of pangolin scales. In this paper, the bionic modeling analysis of chisel type energy-saving subsoiling shovel is carried out by using 3D modeling software. According to the simulation analysis data, we optimize the key structural parameters, and try to produce the bionic energy-saving deep scarifier with reducing viscosity and resistance. In order to study the performance of the chisel type energy-saving subsoiling shovel, L9 (34) orthogonal test was carried out in the field with the number of bionic surfaces, coating materials and forward speed as the experimental factors, and the adhesion soil amount and traction resistance as the test indexes. The results show that the order of influence of each factor on the index is the number of subsoiling shovel bionic surface, coating material and advancing speed; the optimal horizontal combination is that the number of bionic surfaces of subsoiling shovel is 10, the coating material is UHMWPE, and the advancing speed is 6km/h.

Simulation of wear and effective friction properties of microstructured surfaces

Wear and friction characteristics are simulated on metal forming tools with tailored surfaces generated by micro-milling. Friction homogenisation is applied to study surface cut-outs on the meso-scale where the structures are resolved by means of finite element methods and where asperities are represented by a combined friction law appropriate for metal forming. Dissipation based and pressure based Archard wear relations are implemented in a postprocessor, and wear distributions as well as effective friction properties are investigated. Sinusoidal surface structures are able to provide anisotropic structural resistance throughout the progress of wear. A bionic surface structure shows quasi-isotropic structural resistance where sliding directions across the edge directions are benefitial with regard to the wear progress. Experimental measurements from a wear experiment give hints which support the dissipation based Archard relation while more experimental evidence is necessary.

Effects of Laser Melting Distribution on Wear Resistance and Fatigue Resistance of Gray Cast Iron

The coupling bionic surface is generally prepared by laser melting on the surface of a gray iron brake hub, which can allow the brake hub to achieve excellent wear resistance and fatigue resistance. The designs of most previous experiments have been based on independent units that were uniform in their distribution patterns. Although some progress has been made in the optimization of cell features, there is still room for further improvement with respect to bionics and experimental optimization methods. Here, experiments on units with non-uniform distributions of different distances were used to rearrange and combine the bionic elements. This paper is that the original uniform distribution laser melting strengthening model was designed as a non-uniform distribution model, and the heat preservation and tempering strengthening effect of continuous multiple melting strengthening on the microstructure of the melting zone is discussed. The mechanism of crack initiation and the mode of crack propagation were analyzed. The relationship between the internal stress in the melting zone and the crack initiation resistance was also discussed. In this paper, the mechanism of different spacing distribution on the surface of gray cast iron by laser remelting is put forward innovatively and verified by experiments, which provides a solid theoretical basis for the follow-up industrial application.

Thermal performance of axial air cooling system with bionic surface structure for cylindrical lithium-ion battery module

In order to enhance the cooling performance of air, a new type of radiator with bionic surface structure is proposed and applied to a cylindrical lithium-ion power battery pack with axial air cooling in this paper. The computational fluid dynamics (CFD) model of the battery module is established to study the effect of the inlet velocity and structure parameter of radiator with bionic surface structure on the cooling performance. It is found that when inlet velocity is higher than 0.8 m.s−1, the maximum temperature and the temperature difference of the battery module can be maintained within 308 K and 5 K during the 3 C discharge rate, respectively. Then, four structure parameters (thickness, shape, height, and length) of the radiator with bionic surface structure are optimized by the single factor analysis and the orthogonal test to enhance cooling performance and reduce power consumption. The results show that the thickness of plate is the most important parameter influencing the cooling performance and power consumption. Then, the height of bionic surface structure is the secondary parameter, and the shape of bionic surface structure is the parameter with a minimal impact on the BTMS. The best cooling performance can be obtained when the four structure parameters are 0.4 mm, trapezoid, 1 mm, and 61 mm, respectively. As compared with the original radiator, the temperature difference and power consumption of the optimized battery module are reduced by 8.1 % and 15.54 %, respectively, while the maximum temperature varies a little. The optimal case in this research can be widely applied to enhance the cooling performance in air-cooled BTMS.

Numerical investigation on VIV suppression of the cylinder with the bionic surface inspired by giant cactus

Vortex-induced vibration (VIV) responses of the cylinders with the bionic surfaces inspired by giant cactus are numerically studied, and the range of Reynolds number is 8.0 × 103 < Re < 5.6 × 104. The dynamic response of the structure adopts Newmark-beta method. The effects of the height ratios (Ks/D, Ks is the height of the bionic structure) on VIV suppression are discussed in detail, and five different height ratios (Ks/D) include T1 (Ks/D = 0.000), T2 (Ks/D = 0.025), T3 (Ks/D = 0.050), T4 (Ks/D = 0.075) and T5 (Ks/D = 0.100). The VIV response process is characterized by four sub-regions (Region I, Region II, Region III and Region IV). As the height ratios of the bionic structures increase, the range of the large-amplitude-motion region gradually decreases, and the lock-in range is smaller. The maximum amplitude ratio in cross-flow direction decreases from 1.50 (T1) to 0.75 (T5), and it reduces by about 50%. The maximum in-line amplitude ratio decreases from 0.35 (T1) to 0.12 (T5), which reduces by about 65.7%. For T1 and T2, the jump phenomenon of frequency ratio occurs between region II and region III. However, the jump phenomenon of frequency ratio occurs between region I and region II for T3, T4 and T5. The maximum mean-drag-coefficient decreases from 3.00 (T1) to 2.25 (T5), and it reduces by about 25%.

Bionic Design to Reduce Jacking Force for Trenchless Installations in Clay Soil

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 their surface. It has been widely proved that some micro geometrical structures can effectively reduce adhesion resistance. Four kinds of bionic penetration heads were designed by imitating micro geometrical structures inspired by the soil animals. In this work, the real time jacking forces of the bionic penetration heads were measured and compared with a smooth penetration head (control group) without micro geometrical structures. The result indicated that the jacking forces of the bionic penetration heads were smaller than that of the smooth penetration head. This proved that the bionic penetration heads have the ability of reducing adhesion resistance. The vertical concave penetration head got the smallest jacking force, of which the average jacking force was 18.7% lower than that of the smooth penetration head. The interaction between soil and bionic surface of penetration head was discussed on the condition of wet friction. The bionic surface reduced the adhesion resistance by disturbing the soil and braking the continuous water film between soil and the surface of the penetration head.

Effect of squid fin bionic surface and magnetic nanofluids on CPU cooling performance under magnetic field

AbstractIn order to improve the low cooling efficiency of electronic component, a squid fin bionic surface and composite magnetic nanofluids were developed and applied in CPU cooling. Effects of squid fin bionic surface and composite nanofluids Fe3O4‐CNTs (FCNT)/water nanofluids on CPU cooling performance under magnetic field were systematically studied. The impacts of nanofluids mass fraction, wave frequency of squid fin bionic surface, magnetic induction intensity, and Reynolds number on the flow and heat exchange characteristics of magnetic nanofluids were considered. The experimental results demonstrated that the cooling capacity of magnetic nanofluids increases with the increasing wave frequency, magnetic induction intensity, and nanofluids mass fraction. Lastly, the whole experimental system was evaluated by a comprehensive performance index, and it was found that the comprehensive performance is better with higher wave frequency and stronger magnetic field.

Low-velocity resistance distortion and bionic drag reduction for ship-type paddy field machinery

The resistance between mud surface and ship-type paddy field machine hull accounts for a certain proportion of the total mechanical power consumption during the operation process. The special characteristic has been found via preliminary study, it showed that when starting or working at low velocity, the resistance is much greater than the machine working at the rated velocity. This characteristic affects the dynamic matching and structural design of the machine. The critical velocity of resistance distortion was around 0.025 m/s under the setting experimental conditions, and the mechanism of resistance distortion under multi-medium was analyzed. Based on water film drag reduction theory, a macroscopic structure of crocodile's abdominal armor biomimetic drag reduction method was proposed. Two kinds of bionic macroscopic structure ship board were fabricated. The macroscopic structure can introduce more water into the bottom surface of the hull; thicken the water film, which can reduce the travel resistance. Design and manufacture a ship-type paddy field experimental setup with velocity control, and compare the traditional smooth surface ship board with the two bionic macroscopic structure surfaces through orthogonal test. The experiment results demonstrated that the ship board with rectangle gully structure has better drag reduction effect than the hexagon one in the lower velocity. But when the travel velocity approach to the resistance distortion critical point, the hexagon gully structure become better than the other one. Through the orthogonal test, the best drag reduction combination is 2.5 kg load weight, 0.025 m/s travel velocity with hexagon ship board, which decreases the drag by 6.3%. Keywords: ship-type paddy field machinery, low velocity, resistance distortion, bionic, drag reduction, crocodile DOI: 10.25165/j.ijabe.20201302.5417 Citation: Yan G Q, Tian P, Mo J S, Xie H, Wei H L. Low-velocity resistance distortion and bionic drag reduction for ship-type paddy field machinery. Int J Agric & Biol Eng, 2020; 13(2): 7–14.