| In response to the development trend of large-scale,lightweight,and complex spacecraft,thin film antenna structures with the advantages of large area,light weight,and easy deployment are widely used.However,due to the large scale and ultra flexible structural characteristics of thin film antenna structures,their vibration and deformation become increasingly significant during orbital operation,which is particularly serious for spacecraft accuracy damage.It is necessary to conduct vibration control and load and deformation measurements to provide key basic data for later processing.Compared to other measurement methods,flexible strain sensors have become a hot research topic in the field of thin film antenna deformation monitoring due to their advantages such as being closer to flexible surfaces and being able to measure directly.However,the need for high-precision monitoring of spacecraft,extreme working environments,and complex external loads pose stringent requirements for the use of flexible sensors: excellent sensing performance and strong spatial adaptability,making it difficult to achieve breakthroughs in a short time relying on existing design principles of flexible sensing elements.Therefore,seeking a new direction for the design and fabrication of ultra-sensitive and highly adaptive flexible strain sensors has become an urgent problem to be solved.Driven by the strong evolutionary pressure of "natural selection,survival of the fittest",the overall performance of the biosensors has been optimized for hundreds of millions of years.Its sensing performance is far superior to that of human beings,and its excellent performance is highly consistent with the performance requirements of flexible strain sensing technology.Obviously,exploring the excellent sensing function and environmental adaptability of typical organisms provides a new solution and theoretical basis for solving the problem of flexible strain sensors for large-scale aerospace structures.In this paper,Heterometrus petersii was selected as a bionic prototype to study the excellent mechanical quantity sensor on the body surface of scorpion-the slit sensillum.The excellent sensing mechanism was revealed,and its structure and material properties were explored.Based on this,a bionic hypersensitive flexible strain sensor was designed based on the principle of coupled bionics,and corresponding preparation methods with clear structure and controllable morphology/ size/ composition were explored.The prepared sensor was used to characterize sensing performance and extreme operating condition adaptability.Based on this,a bionic hypersensitive sensor array was designed and fabricated,and its application in thin film structures was explored.The main research content of this article is as follows:(1)The slit sensillum of scorpions were selected as the research object,and the morphological characteristics,internal structure,material composition,and mechanical properties of scorpion slit receptors were studied using a combination of ultra depth of field microscopy,semi thin sections of biological tissue,field emission scanning electron microscopy,Fourier transform infrared spectroscopy,and atomic force microscopy.The unique characteristics of soft and hard interlaced sheet stacking structures of scorpion slit receptors were learned,and it was analyzed that the soft and hard interlaced sheet stacking structure made the slit receptors have the safety of bearing the main structure.The biological model and sensing mechanism model of the scorpion slit sensillum were established by observing the vibration excitation response process of the slit sensillum using a super depth of field microscope.Based on the previous research foundation of the research team,the packaging and protection effects of the skin membrane of the seam receptor to insulate rainwater and prevent external interference from staying in the internal cavity were analyzed to improve the environmental adaptability of the scorpion seam receptor.(2)Based on the experimental analysis results of the functional mechanism and structural characteristics of the scorpion slit sensillum,and based on the coupled bionic theory,a bionic hypersensitive flexible strain sensing element was designed.A sensor with "epidermal like membrane" packaging layer of functionally matched receptor epidermal membrane,a layered structure consisting of a controlled crack array conductive functional layer inspired by a sensing unit and a low elastic modulus flexible substrate layer.Realize highly reproduce the sensing function and structural materials of the slit sensillum.And then explore high-quality preparation methods for bionic hypersensitive flexible strain sensor,and analyze the main influencing factors in the preparation process.The prepared bionic hypersensitive flexible strain sensor has the characteristics of ultra-thin and ultra-flexible,and the combination between various layers is well.(3)The performance of bionic supersensitive flexible strain sensor was tested: the sensitivity characterization value GF was up to 6927.9,the response time was less than134 ms,and the drift was less than 0.092%,and shows extremely strong stability after more than 20000 cycles.It is proved that the sensor can meet the needs of high-precision monitoring of large-scale aerospace structures.In addition,the sensing characteristics of the sensor under extreme working conditions were explored,including the research on the resistance to extreme temperature difference,the waterproof performance test and the high load bearing characteristics.The bionic hypersensitive flexible strain sensing element showed excellent adaptability under extreme working conditions.(4)The application performance of the bionic super-sensitive flexible strain sensor was explored,such as its application in the field of medical treatment,speech recognition,airflow monitoring and water drop monitoring,etc.,which verifies the super-sensitive sensing ability and excellent performance of the prepared bionic sensing element,and expands its application field.Then a bionic super-sensitive flexible strain sensor array is designed to simulate its application in the field of deformation monitoring of large-span membrane structures.The prepared bionic super-sensitive flexible strain sensor array can accurately identify various deformation of membrane structures. |
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