| Strain sensors are widely used in various fields.As a common transducer element,it has become the most common type of transducer in a variety of sensors.That is to say,strain sensors are used to convert strain of transducer into electric quantity in various types of acceleration sensors,force sensors,weight sensors,etc.In addition,with breakthroughs in the field of smart materials recently,and the bio-inspired sensing structures or materials,strain sensors based on the electron tunneling effect,the field emission effect or the seepage effect,have become hotspots.With the advanced in large data,cloud computing and networking concepts,as well as the related technology,all kinds of strain sensor,especially flexible sensor act as wearable devices,advanced man-machine interface and virtual integration and natural interaction which are the basic components,have been widely concerned.In China's recent "13th Five-Year" national scientific and technological innovation planning,the national long-term scientific and technological development plan(2006-2020),China Manufacturing 2025 and others policy guidance documents,"the development of human-computer interaction technology,focuses on intelligent perception and cognition,interaction with the natural fusion,wearable technology development and application" were put forward.All of the documents listed "strengthen the new sensor technology and technology development","to accelerate human intelligence interaction" as focus.The new intelligent perceptual sensor is the basis of the intelligent and networke system,which can perceive the environment,the interaction of information and the realization of "human machine communion".As an important field of bionics,bio-inspired sensors are bio-inspired designs,which dedicated to measurements.They are designed to convert and output signals according to certain rules,with new detection principles or sensing structures.The sensors are composed of sensitive elements and transducer elements.Besides,signal adjustment circuit,power supply and other auxiliary equipment are necessary.Bionic design covers two major aspects: First,bionic sensitive mechanisms,including the bio-inspired sensitive structures and sensitive materials;Second,bionic function.Bio-inspired sensitive structures and bio-inspired sensitive materials(also known as bionic smart materials)are the key of bio-inspired sensors.In this paper,from the perspective of coupling bionics,Heterormetrus petersii is selected as biological model.Inspired by the biological characteristics of the ultra-sensitive crackshaped slit sensilla to external vibration,the bionic strain components were designed and fabricated.In addition,the performance of the bio-inspired strain-sensing components were studied and tested,and the application test was studied.The main contents of this paper are as follows:Firstly,the biological structure and material properties of the slit sensilla were observed and analyzed,and the mechanism(strain perception)of the biosensor was explained by combining the biological function and structure of the slit sensilla.That is,after comparative analysis of different types of scorpion specimens collected,the Heterormetrus petersii is selected as biological model.The surface morphology and 3D structure of the slit were observed by scanning electron microscopy(SEM),?-CT and ultrathin histological slice.So that,the structural characteristics were obtained.The mechanical properties of the biomechanical material of slit organ were studied by nano indentation.From the perspective of functional morphology,the mechanism of vibration perception of slit was explained,according to the biological structure,material properties and biological function.Secendly,the stress/strain magnification models were established,which were based on the coupling of structure and material.That is,the model revealed the mechanism of stress/strain efficient amplification of the slit.Then,the amplification efficiency is calculated.The stress/strain magnification models are based on the structure-material coupling of the slit,which are according to parameters such as the structure,the feature size and the material properties.The discontinuous rigid layer and the flexible layer model(stress-magnification),and the rigidflexible coupling of brick-embedded-mud model(strain-magnification)are established.According to them,the mechanism of ultra-high sensitivity of slit is explained.In addition,its amplification efficiency is figured out.Then,both of the bio-inspired discontinuous rigid layer and the flexible layer coupled stress-sensing-structure,and the bio-inspired rigid-flexible coupling of brick-embedded-mud stress-sensing-structure were designed and fabricated.The performance of the prepared structures were tested and the parameterized design criteria were established.After the two bioinspired stress-sensing-structures are designed and fabricated,performance tests were conducted.The test results indicated that the prepared bionic strain sensing components has the advantages of high-sensitivity and superfast-response.Based on the amplification efficiency calculation results,the parameterized design criteria of strain sensing structures inspired from slits were established.Finally,the application test of both two bio-inspired strain-sensing components were studied and conducted.In addition,the auxiliary circuit was designed and manufactured.The application test results show that the bio-inspired strain-sensing components have wide potential application in the fields of human physiological index detection and human motion monitoring.In particular,due to the high-sensitivity and superfast-response of the bio-inspired strain-sensing component,it can be used to detect the movement of the human body in noncontact,by detecting the vibration signals caused by human's movement.It achieved the noncontact detection of human movement.Such that,the non-contact detection process is similar to the biological function of scorpion vibration perception. |
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