Biology Coupling Characteristics On Soil-engaging Components Of Mole Crickets

Bionics is to imitate the principles of biosystem and to create corresponding techniques or make the artificial system possess the characteristics of biosystem. Since bionic origination, great achievement has been got in many fields such as morphology bionics, bionic structure, biomaterials, and functional bionics. As the development of bionic research, complex problems have been found difficult to solve under the condition of using bionics method include one or two kinds of field. More and more research have presented that a private function of one animal was achieved by the cooperation of surface morphology, tissue structure and component material factors. We can also call this cooperation of factors which are advantage to the function's achievement as"biological coupling". Bionics based on the mechanisms and principles of biological coupling is"coupling bionics".Mole crickets (Gryllotalpa orientalis) lives in the sand soil. When they are digging underground rapidly, their body rubs against the soil. The research of biological coupling of typical parts of mole crickets should be useful to the research of coupling bionics, especially in the development of reducing friction and wear. Mole crickets have been studied in both entomology and bionics under the idea of biological coupling. Every decisive factors of function have been found and their separate effect and corporate cooperation in the special environment have been studied.The foreleg, tergum and forewing of mole crickets have been chosen as typical parts. The photo of them were screened by stereomicroscope of SteREO Discovery V12,scanning electron microscope JSM-5310 and transmission electron microscope EM-1200EX. The typical parts in the photo have been observed and analyzed.The wear form between foreleg and soil is low stress abrasion. The structure of the palm, the configuration of each structure and surface morphology of claws cooperated to achieve the function of wear resistance. Claw, tarsal dactyls and feathered spur are important dig parts on the plam. Among them claw is most important, the other two are assistant. Different part have different configuration. The claw is wedge-shaped with the wedge corner of 30?. The shape of the top claw is obtuse which resembles the shape of clod, so it can be help for reduce wear. Setae distribute densely on the surface of the palm, which is morphology factor and can absorb the shock of soil. The factor of structure, configuration and morphology of foreleg are not independence, but cooperate and compound in order to realize the function of wearable and be most beneficial for digging.The wear form between tergum and soil is impact abrasive wear and low stress abrasion. The surface morphology, tissue structure and component material cooperated to achieve the function of resisting the impact abrasive wear. Soft setae distribute densely on the surface of the tergum, which can form a flexible layer and reduce the shock and wear of soil. When the mole cricket moves, setae dither constant ly, that is due to the basal ring contacted setae and tergum. The dithering can be help for reduce adhere. The distribution of setae is linear, which obeys the principle of optimization and can make more achievement under using less setae number. Vertical layered structure present on the section of tergum. The structure is composed by long and short setae and thorn on surface and piled tissue layers undersurface. As the distance between layer and surface get longer, the tissue become more and more flexible. The flexible tissue can reduce shock and the rigid one can protect tissues in it. On the tergum, there is a special material chitin. Chitin and denatured protein compound a complex material, which can be rigid or flexible depends on the degree of protein's denaturation. The achievement of wearable of tergum is the result of coupling with all of these factors.The wear form between forewing and soil is low stress abrasion. The combined configuration in macro and micro and microtriche morphology on surface cooperated to achieve the function of wear resistance. In micro, wing is composed by vein and wing cell. Vein present like a net and enhance the strength of wing. In section of wing, vein seem like a pipe with thick horniness around, which have less weight and more strength. In micro section, layer structure in wing with the rigidity from rigid to flexible is the same as in tergum. It can resist pressure from soil as well as reduce shock. In material, the effect of reducing wear can be realized by chitin layer on the surface of wing. Chitin and denatured protein compound a complex material, which can be rigid or flexible depends on the degree of protein's denaturation. In morphology, the microtriche make the effect of protecting wing from scraping with soil. Water membrane between soil and wing distribute as non-uniform and discontinuity because of the microtriche, which can reduce the thickness of water membrane and the area of wetting in order to reduce friction. It present as needlepoint at the top of the microtriche, which can also reduce friction. The achievement of wearable of wing is the result of coupling with all of these factors. The wearable characteristic of coupling is formed by acting between wing and soil.The wearable function of foreleg, tergum and forewing is realized by the cooperation of many factors. Because of this, foreleg, tergum and forewing are systems with wearable function. The three systems, with different form of wear and actions in contacting with soil, cooperated together, forming the wearable function of mole crickets.The distribution of setae on is analyzed by using statistical method. The result shows that the number of setae, paralleling the direction of the growth of setae, is less than the vertical direction. This form can be help for reducing wear. A model of tergum is reconstructed by using reverse engineering. Curve fitting is done by matlab software, using the data of profile point of tergum in horizontal and longitudinal direction. Curvatures and second derivatives of profile curve are calculated. The variational principle of tergum's surface is analyzed.The bionic coupling research of biology character based on wearable function of mole crickets is just a preliminary exploration. The biology research provides a firm foundation to the technology of wearable bionic coupling. More work shall be done, such as the research of coupling method, establishing of coupling model of typical parts, kinematics and dynamics analyse of mole crickets and so on.