Abstract: Bionics is a new frontier science and provides many inspiration and thoughts for human invention. Through discussing the classification of bionics, it can greatly improve the capacity of human’s adaptation for nature and productivity as well. It can also have great social and economic benefits. Besides, the reason that restricts bionics development is expounded. Development of bionics can’t last long without the cooperation with many other subjects, and its own development also promotes the development of these disciplines. Furthermore, it is development trend of bionic that to achieve more perfect imitation and reengineering of nature, to discover and develop its relevant theories and technical methods. Therefore, bionics plays more and more important role in innovation and has broad prospects in the research.
Abstract: Thin-walled spatial bending tube can not only provide engineering design with higher flexibility and lighter structure, but also enhance the construction of space saving and aerodynamics improvement. Based on rotary draw bending technique, a new method for spatial consecutive bending with no straight line for thin-walled tube was put forward. Firstly, a new bionic elastic mandrel was developed by analyzing the structural characteristics of the squilla. It mainly consisted of bowl-shaped mandrel balls, an elastomer and a mandrel shank. The bowl-shaped mandrel balls, nested matching one another, generated a non-smooth surface which can provide continuous support for internal surface of the tube wall. It could also achieve small bending radius. The elastomer featured of certain bending stiffness and enough tensile strength. Secondly, a curved clamping die was advanced to clamp the spatial consecutive bending tube with no straight line effectively. Based on the shape of the bending tube after the former bending forming process, the curved clamping dies which can match the shape of the former bending tube were designed for the later bending. Lastly, bending experiments was performed. A thin-walled tube made of Q235 with two passes, one bending angle 90° and the other 180° was taken for example and the spatial consecutive bending tube with no straight line was successfully obtained. It is of significant importance in enriching the spatial bending tube technique and achieving the small bending radius.
Abstract: In this manuscript, a muscle-like linear actuator based on the combination of Bi-IPMC linear actuator unit was developed focusing on the applied requirements in the biomimetic artificial muscles using as the actuators. Subsequently, the muscle-like linear actuator was mainly fabricated by two segmented IPMC film, which is obtained through a special process and the actuation performance of the muscle-like linear actuator was further experimented by the testing platform. The results found our actuator behaved a high displacement performance, and this kind of muscle-like linear actuator has a potential value in the engineering practice.
Abstract: In this paper, a numerical simulation of three dimensional model of IPMC actuated fin of a fish like micro device is presented using two-way fluid structure interaction approach. The device is towed by the surface vessel through a tow cable. Fin is acting as dorsal fin of the fish to control depth of the device and also acts as a stabiliser against its roll motion. Fin's displacement disturbs water flow streamlines around it, as a result velocity and pressure profile of fluid's domain changes around the actuated fin. As fin's position continuously changes throughout its actuation cycle, this makes it transient structural problem coupled with a fluid domain. Fin's displacement is received by the fluid and resulting fluid forces are received by the fin making it a two-way fluid structure interaction (FSI) problem. Such problems are solved by multi field numerical simulation approach. This multifield numerical simulation is performed in ANSYS WORKBENCH by coupling transient structural and Fluid Flow (CFX) analysis systems. It is desirous to determine the torque acting on the fin due to fluid forces through its actuation cycle by IPMC actuators. The objective of this study is to develop the methodology (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the IPMC actuated fin, subjected to large displacement against different flow speeds. Efficacy of fin as depressor and riser is also required to be judged by monitoring the forces acting on wing in response to its displacement under IPMC actuation. Same approach is also applicable to the self-propelled systems.
Abstract: A physical mesh-less soft tissue cutting model with the viscoelastic creep characteristics has been proposed in this paper. The model is composed of filled spheres which are connected by Kelvin structure, so as to realize the cutting with viscoelastic creep characteristics. Then, it is further compared with the mass spring model in order to verify the effectiveness of the model. Secondly, a range-based Smoothed Particle Hydrodynamics (SPH) method with variable smoothing length is proposed, in order to simulate the blood flow simulation effect in the virtual surgery training system. Finally, the two are combined to be applied to the kidney soft tissue cutting experiment in surgery trainings. Experiments show there is a significant improvement on the cutting and simulation effect in terms of the viscoelasticity of the soft tissue cutting and the pressure and viscous force of blood flow.
Abstract: Silymarin is a unique flavonoid complex isolated from milk thistle (Silybum marianum). It has been widely used as a hepatoprotective agent. Orally administered silymarin can be absorbed rapidly but only 20-50% of silymarin will be absorbed through gastrointestinal tract, resulting in low bioavailability. Those limitations are due to its low solubility, either in water and oil, and its low intestinal permeability. This study was aimed to develop silymarin-containing phytosome in order to improve the bioavailability of silymarin with sufficient safety and stability. This system consisted of silymarin-phospholipid complex prepared by solvent evaporation method, which was incorporated to form phytosome vesicles using thin layer method with various concentrations and molar ratios of silymarin and phospholipid. The vesicle size of phytosome was reduced with sonication. The results demonstrated that formula with 2% silymarin-phospholipid complex and molar ratio of silymarin to phospholipid of 1:5 showed the best phytosomal characteristics, with mean vesicle diameter of 133.534 ± 8.76 nm, polidispersity index of 0.339 ± 0.078, entrapment efficiency of 97.169 ± 2.412 %, and loading capacity of 12.18 ± 0.30 %. The preparation remained stable after freeze-thaw stability test. Analysis of Infrared spectroscopy and Differential Scanning Calorimetry confirmed the presence of physical and chemical interactions between silymarin and phospholipid within complex formation. Well formed and discrete vesicles were revealed by Transmission Electron Microscopy analysis, drug content measurement, and freeze-thaw stability test.
Abstract: There are numerous clinical indications for bone grafts. The ideal graft material should favor bone apposition and growth while simultaneously being degraded by body fluids and cells. Ultimately, the material should be replaced by mature bone tissue within a healing period of weeks. Because autologous and allogenic bone grafts fulfill some of these requirements, these biological materials are routinely used by clinicians. However, biological materials have intrinsic limitations. Harvesting autologous bone requires a second surgical site, which can cause complications, the material is limited in quantity, and it may lead to immunogenic rejection or transfer certain pathogens and viruses [1-3]. For these reasons, researchers and clinicians have developed synthetic bone substitutes. Our approach has focused on composite biomaterials that combine bioceramics with hydrogels to replace and regenerate bone tissue in osseous defects.
Abstract: Magnetron sputtering techniques was used to deposit TiN, TiO2 single layer and TiN/TiO2 multilayer coatings on 316L stainless steel (316L SS) substrates. The crystallinity, surface topography and roughness parameters of uncoated (316L SS) and coated specimens were examined. The anti adhesion and antibacterial behavior of S.aureus (gram (+) ve) and E.coli (gram (-) ve) strains on uncoated and coated substrates were determined by live/dead staining using epifluorescence microscopy. Results demonstrate that the coated samples undergo drastic reduction of bacterial adhesion and negligible effect of antimicrobial activity. Further, coated substrates exhibit less platelets activation than that of uncoated substrates.
Abstract: Magnesium-substituted hydroxyapatite coatings have been deposited on magnesium alloy for biomedical applications by sol–gel technology. The Ca(10−x)Mgx(PO4)6(OH)2 coatings obtained, with magnesium contents up to x = 1.5, show dense and compact and with visible cracks. The results of Hydrogen (H2) evolution testing in Hank’s solution show that magnesium-substituted hydroxyapatite coatings can improve the corrosion resistance of magnesium alloy.
Abstract: The controllable deposition of hydroxyapatite (HA) on femtosecond lasers micro-patterned Titanium (Ti) plates was studied in simulated body fluid (SBF). Energy Dispersive Spectrometer analysis and X-ray Diffraction (XRD) analysis show that the hydroxyapatite deposites on the pattened titanium surface in 1.5 SBF and SEM studies show three growth modes of HA (homogeneous hydroxyapatite layer, needle-like structure, and plate-like structure) deposited at different spots of the Ti plate surface. This stereo reticular structure of hydroxyapatite could be regarded as promising candidate material for metal implantation.