Papers by Keyword: Biomimetic

Abstract: Superior to hardwood and softwood trees, coconut palms are able to withstand extreme weather conditions without failure. Previous studies have shown that the internal structure of coconut palm stems significantly differs from hardwood, softwood and even other palm stems, in terms of fibre orientation and density distribution, likely influencing the mechanical characteristics of the tree. This paper aims at quantifying the cocowood hierarchical structure at an integral level (stem structure). To achieved this, quantitative analysis of more than 40 senile coconut palms from Fiji and Samoa has been carried out. This paper defines and analyses the typical cocowood morphology (form-structure) in terms of such factors as characteristic radius, fibrovascular bundles orientation and density distribution. For the first time, the characteristic triple helix configuration traced out by the fibrovascular bundles within the cocowood structure is modelled for the whole coconut stem. Specific equations are proposed to determine these factors at any given position in the tree. Knowledge advanced from this study will provide a scientific basis for future cocowood biomechanics research, including finite element modelling and analysis for biomimetic engineering applications.

Abstract: This paper presents an overview of jumping robots and the methods used to stimulate them for their movements to prey something or escape themselves. The locomotion type is generally divided into two groups, i.e. directly actuated and indirectly actuated jumping robots. Three examples from the former and four of later class are analyzed in detail and their structures are presented with self-explained pictures. The advantages and disadvantages of each class are also discussed. On the basis of the analysis, it can be observed that directly actuated jumping robots are having more advantages comparatively and some future work is suggested to eliminate their flaws and make them more reliable.

Abstract: Biomimetic is the field of engineering which involves analyzing the biological beings and incorporating their designs and systems for manufacturing mechanical systems. An Ionic Polymer metal composite (IPMC) is a smart material that displays a significant bending and tip force after the application of a low voltage. It is light-weighted, flexible, easily actuated, multi-directional applicable and requires simple manufacturing. In this paper, a two-link biomimetic knee joint mechanism of a grass hopper is presented. Secondly, an IPMC pair of strips is proposed as a link that enables the actuating force which is modeled on the basis of the grass hopper's leg. Thirdly, dynamic model is developed for the proposed mechanism through Lagrangian mechanics. Fourthly, power series is utilized for the solution of the non-linear transcendental model. Wolfram mathematica is employed for the simulation of the model. Finally, the effect of torque is analyzed by varying the actuating torque. It is concluded that actuating torque is directly proportional to the angles moved and inversely proportional to the potential energies of the linkage. Furthermore, a stiffer and more vibrant linkage is observed as per simulation results. These results are validated theoretically. Our simulation results indicate that the proposed IPMC has the potential for utilization in small biomimetic applications like insects robots joints activation, underwater fish fins, surgical grippers, synthetic ventricular muscles and human catheter system for endoscopic surgery and diagnostics etc.

Abstract: This paper reports the fabrication of nanofiber scaffolds with dual gradients in both mineral content and fiber orientation, which can be used to mimic the composition and collagen fiber organization at native tendon-to-bone insertion site. Such scaffolds show great potential for rotator cuff injury repair.

Abstract: Titanium and titanium alloys have been extensively studied for many applications in the area of bone tissue engineering. However, dense titanium is prone to lead into aseptic loosening due to their high elastic modulus compared to natural bone. One way to lower the elastic modulus is to produce a porous structure of the metallic alloy by adjusting its porosity. Another concern is the bioinertness of titanium that have no direct chemical bonding with surrounding tissue. One approach to improve the healing process is the application of a calcium phosphate coating onto the surface of biomedical devices and implants. Biomimetic creation of surface using alkali heat treatment with silica addition was employed in this study. The porosity of the samples ranges from 60% to 70%. It was demonstrated that the biomimetic methods are suitable for inducing apatite on the titanium alloys surface.

Abstract: A novel method for preparing oleophobic surface is presented. In this article, an oleophobic surface on X70 pipeline steel was prepared successfully by the combination of shot blasting, hydrochloric acid aqueous solution etching, and modified with low-energy material. The influences of the concentration of hydrochloric acid and chemical etching time on the oleophobicity were analyzed. And the optimal experimental parameters were determined. The surface morphology and chemical composition were observed by the field emission scanning electron microscopy (FESEM) and energy dispersive spectrometer (EDS), and the contact angle was measured by contact angle meter. The results showed that micro-nanocomposite structure on the substrate was formed after shot blasting and chemical etching of hydrochloric acid aqueous solution. After low-energy modified, the specimen obtained the better oleophobicity, and the maximum contact angle between the surface and peanut oil was 140°.

Abstract: This paper summarizes a TEDx Talk that the European physics professor Ille C. Gebeshuber, who has been living in South East Asia for nearly five years now, gave to a live audience of 800 in Kuala Lumpur, Malaysia, in July 2012. A similar talk is also given as an invited lecture at the 4^th International Conference of Bionic Engineering in China in August 2013. The talk highlights the importance of news ways of doing science and of doing engineering that are needed to successfully address the major challenges humankind is currently facing, and how a generalistic approach synergistically combining Eastern and Western thinking might help in this respect. Biomimetics is stressed as an integrated, generalist way of learning from living nature, and as best practice example for developing new approaches that are based on understanding rather than learning by heart, with memory, reason and imagination as pillars, bridging fields of specialization and of education and thereby blending the knowledge of single isolated scientists and specialist scientist networks to a wisdom of the whole, powerful enough to help us successfully address our major problems.

Abstract: This paper deals with imitating a novel type of biomimetic integrated composite with porous core layer from the beetle elytra microstructures. Firstly,the microstructures of the elytron of Anoplophora Glabripennis, Anomala Corpulenta Motschulsky, Prosopocoilus Inclinatus and Melolonthidae were examined with SEM. Inspired by these structure characteristics, a biomimetic composite model was proposed, in which the two face layers were interconnected with a porous core layer, and there are continuous fibers embedded into these three layers to enhance mechanical performance of the laminated composite. Then a specimen of this laminated composite with porous core layer was made. The procedures include: weaving a piece of two layers space fabric by glass fibers as the preform of the composite,filling the mixed resin which contained 50% granular paraffin wax and 50% epoxy resin into the space of the fabric, putting it into a flat mold, keeping 36 hours, and finally heating the composite to remove the paraffin wax to form the porous core layer. The experiment showed that the model of integrated porous core laminated composite inspired by the beetle elytra structure is reasonable and this novel type of lightweight composite material was manufacturable.

Abstract: Perching with Unmanned Aerial Vehicles (UAVs) has been an emerging topic in the field of biomimetic engineering during last decade. Taking the newly designed gripping mechanism into account, a control strategy for autonomous perching with a quadrotor is further proposed, implemented and validated in this paper. Based on the perching procedure of birds in nature, this article focuses on the steps of engaging with the target during perching, latching to the target after engagement and releasing from the target when de-perching. The autonomous control strategy is integrated into the gripping mechanism after it is derived. Experiments on its effectiveness and reliability with a quadrotor are finally conducted, showing that the control strategy is capable of autonomously perching a quadrotor to a target pole.

Abstract: Composites based on calcium phosphates (CP) and mixtures of biopolymers (chitosan and hyaluronic acid) have been prepared by a biomimetic co-precipitation method and tested as scaffolds for bone tissue engineering. The biomimetic strategy is inspired by natural mineralization processes, where the synthesized minerals are usually combined with proteins, polysaccharides or other mineral forms to form composite, in physiological conditions of temperature and pH. Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffraction and XPS analyses confirmed the porous morphology of the scaffolds and formation of various forms of calcium phosphates with amorphous nature. The in vitro degradation studies showed a slow degradation process for CP-biopolymers composites and limited swelling in simulated body fluids. The scaffolds compositions have no negative effect on osteoblasts cell, emphasizing a good biocompatibility.