| As a gas detection tool,gas sensors have been widely used in various fields such as medical health,life safety,environmental protection and industrial production.After long-term work,the sensitivity and stability of some gas sensors will decrease.At present,researchers mainly try to improve the sensitivity and stability of the sensor by developing new gas-sensitive materials and optimizing the distribution and structure of gas-sensitive materials.In recent years,bionics is a fast developing frontier subject,and its research results have been widely applied to many engineering fields.Biologists have found that scorpion has sensitive chemical sensibility and its pectine is one of the many receptors of scorpions that has the ability of quickly sensing chemical substances.The relationship between the sensation mechanism of scorpion pectine and its structure is still unclear.The perception mechanism studied from the perspective of bionics and the design and manufacture of biomimetic sensing structures have not been reported yet.It is an innovative work.In this paper,based on bionics,we compared and analyzed the gas sensitivities of three typical scorpions with chemical sensibility,and selected the scorpion with higher gas sensitivity as the research biological model to observe the structure of scorpion pectines,analyze the chemical mechanism of scorpion pectines,design and manufacture the surface of bionic composite structure and teste its gas sensitivity.Firstly,we compared and analyzed many kinds of scorpions and selected three typical scorpions(Heterometrus petersii,Parabuthus transvaalicus,Buthus Martensii)with chemical sensing ability as biological prototypes.Subsequently,we compared the sensitivity of three kinds of scorpions to ethanol and ether gas through behavioral tests,and chose scorpions(Buthus Martensii)as the research prototype.We used the scanning electron microscope,atomic force microscope,X-ray threedimensional microscope and other observation ways to characterize the surface morphology and the two-dimensional and three-dimensional structures of scorpion pectines.Pectines are located in the scorpion abdomen,composed of two separate comb-shaped structure;and comb structure is composed of a series of neatly arranged combs and ridges.A large number of pits and columnar structures are distributed on the flanks of the comb near the abdomen of scorpion.Based on the structure of scorpion pectines,we established a series of biomimetic structural models by using CATIA software and conducted ANSYS-FLUENT fluid simulation analysis to explore the relationship between the structure and gas sensitivity of scorpion pectines and reveal the mechanism of high gas sensitivity of scorpions(Buthus Martensii)based on structure.Finally,we designed nine bionic models based on the morphologies and structures of the scorpions pectines(Buthus Martensii).We established biomimetic structural models by using CATIA software and manufactured them by using 3D non-metallic printing technology.A uniform layer of zinc oxide was formed on the surface of the biomimetic samples through chemical method,and its surface was characterized by using scanning electron microscopy.Then,a gas sensitivity test system was set up to test the rate of resistance of bionic samples which can indicate the gas sensitivity of the bionic samples to some extent.The results show the primary and secondary factors that affect the rate of resistance change(Pit diameter B,base arc curvature A,pit spacing D,convex structure width/arc length C)and the best combination of the factors resulting in the highest resistance change(A = 30°,B = 2.6 mm,C = 1.0 mm/1.0 mm,D = 2.7 mm).And the gas sensitivity of the optimized combination sample is 1.23 times stronger than that of the planar smooth sample.Through regression analysis we also get the regression equation between the various elements.This article aims to provide a new method for improving performance of the sensor. |
