The Mechanical Properties Of Flexible Electronics Microstructures And Its Application

A flexible electronics microstructure(serpentine structure)with ultra-low rigidity,ultra-high tensile performance,complexity(rich design space)and conciseness(simple described rules),not only shows excellent mechanical properties,but also can realize flexible control through three-dimensional assembly technology,so it has a wide range of applications.The research on the mechanical properties of flexible electronics microstructures and its application is complicated,which has become the bottleneck barrier restricting the application and development of flexible microstructures in the fields of micro electronic devices,biomedicines and metamaterials and so on.In this paper,the mechanical properties of flexible electronics microstructures and its application are studied,on this basis,in order to establish a comprehensive and detailed theoretical model of buckling and vibration of flexible microstructures,construct a design scheme of flexible microstructure that matches the shape of organoids,design flexible multidirectional strain sensor with ultra-low rigidity and neglectable influence on the strain field and design a microstructural vibration measurement system that can synchronously measure the mass and modulus of cells(or other biological tissues),which provide theoretical basis and technical support for exerting the mechanical properties of flexible microstructures and guiding the application of flexible microstructures.The main research contents of this paper are as follows:?.Establishment of the theoretical model of buckling of flexible microstructuresIn order to obtain the analytical expressions of critical load,displacement and surface strain distribution of flexible microstructures during buckling,a theoretical model for the buckling of flexible microstructures is established,and the criteria of the flexible microstructures buckling is proposed.Under certain conditions,the buckling of flexible microstructures can be reduced to the Euler buckling,and the effective bending rigidity of flexible microstructures is derived.This research has important academic significance and application value for guiding the design of biologically related microstructures as well as exerting the excellent mechanical performance of three-dimensional assembled flexible microstructures.?.Establishment of the theoretical model of vibration of flexible microstructuresIn order to obtain the analytical expressions of the resonant frequency and mode of the flexible microstructure,the theoretical model of vibration of the flexible microstructure is established,the relationship between the vibration frequency of the flexible microstructure and its sizes parameters is analyzed,and the ultra-low resonance frequency characteristics of the flexible microstructure is explored.Under both symmetric and asymmetric conditions,the scaling laws of resonant frequency for the arbitrary shape flexible microstructures are proposed.?.Customization of the shape of the three-dimensional flexible microstructureIn order to customize the shape of the three-dimensional flexible microstructure to match with the organoids,the sizes of the flexible microstructure are inversely designed and the design schemes of shape of the three-dimensional flexible microstructure are constructed.On this foundation,the principle of shape customization of flexible microstructures and the influence of effective bending rigidity on the design schemes are explained.Under both fixed and simply supported boundary conditions at both ends,by using finite element method,the rationality of shape customization scheme is verified.?.Design of the flexible multidirectional strain sensorIn order to monitor the strain on the surface of skin or other flexible materials in real-time,a flexible multidirectional strain sensor is designed.The designed flexible multidirectional strain sensor,not only has ultra-low rigidity,but also has little influence on the strain field.On this foundation,the principle of flexible unidirectional strain sensor and multidirectional strain sensor are explained,by using finite element method,the validity of the flexible unidirectional strain sensor and multidirectional strain sensor for strain measurement are verified.?.Construction of the flexible microstructural vibration measurement systemIn order to synchronously measure the mass and modulus of cells(or other biological tissues),based on the ultra-low resonant frequency and convenient tunability of flexible microstructures,a microstructural vibration measurement scheme is designed,to realize the multi parameter monitoring of cell properties during the process of cell growth or cell interaction with the surrounding environment(such as drugs and viruses).Based on the scaling law of the resonant frequency of the flexible microstructure,the reasonable and effective design of the microstructural vibration measurement system is constructed to adapt other types cells or organoids.On the basis,the effects of vibration frequency measurement accuracy,fluid environment and the frequency depended modulus of cells on the microstructural vibration measurement system are discussed.In conclusion,the mechanical properties and its applications of flexible microstructure are studied,the mechanism of improving the mechanical properties of flexible microstructures by controlling the two-dimensional to three-dimensional assembly process are discussed.On this basis,the reasonable and effective shape customization scheme of flexible microstructure,flexible multidirectional strain sensor and microstructural vibration measurement system are constructed,which provide theoretical basis and new ideas for exerting the excellent mechanical properties of flexible microstructure and making it have a broader application prospect.