Research On Strechable Electronic Devices And Its Applications For Smart Microsystems

With the merits of miniaturization,flexibility,and multi-functional integration,wearable electronics have become an important part of the Internet of Things,penetrating various aspects of modern society,economy,life,and security,covering information communication,military defense,healthcare,entertainment,sports and so on.However,whether as sensors for signal acquisition or as mobile terminals for data conversion,the in-depth use and inventive development of wearable electronics still face many technical challenges and bottlenecks.Among them,the key difficulty lies in effectively solving the surface heterogeneous integration problem,distributed reliable energy supply problem,and multi-functional smart integration problem,which are inevitably required by the wearable practical scenario.To address the above key scientific issues,one of the practical and effective strategies is to study micro-nano cross-scale stretchable electronic integrated manufacturing technology,develop metal-based/flexible-based/composite-based heterogeneous integrated processing,and then explore the hybrid micro-nano energy harvesting and advanced micro-nano sensing technology with stretchable characteristics,and ultimately achieve wearable sensing and energy supply integrated smart micro-nano system.To address the above points,in this dissertation composite functional electronic materials are explored for potential breakthrough in this field.Combined with ductile structure design,heterogeneous-based micro-nano cross-scale stretchable electronic integration manufacturing technology is studied,which offers flexibility,ductility,and surface adaptability,and provides a solution to the problem of surface heterogeneous integration.Based on the above manufacturing method,combined with the organic fusion of multi-source and multi-mode micro-nano energy transfer mechanism,a high-performance micro-nano energy harvesting device for harvesting biomechanical energy is proposed and realized,providing a solution to the problem of distributed reliable energy supply.Specifically,the research works were purposefully carried out in this dissertation:Based on the research of triboelectric,piezoelectric,and electromagnetic micro-nano energy harvesting mechanisms and device structures,three types of core functional structures of triboelectric dielectric layer,piezoelectric composite layer and conductive electrode layer are studied.Through key process parameters extraction and optimization,the electrospinning and alternate blending based-heterogeneous integrated manufacturing technology for stretchable micro-nano energy functional materials is proposed,enabling the realization of three stretchable micro-nano energy harvesters for biomechanical energy harvesting.Through electrical performance characterization and test analysis of open-circuit voltage,short-circuit current,matched load,capacitive energy storage,etc.,combined with COMSOL multi-physics field coupled finite element model optimization,a micro-nano energy harvester with 900%super-stretchability and surface adaptability has been demonstrated,with the output power density up to 21.7 W/m~2.This demonstrates the important prospect of stretchable micro-nano energy harvesters to effectively harvest biomechanical energy and convert it into electricity in a wearable scenario,providing a long-cycle stable energy supply for low-power-consumption micro-nano electronics.Based on the study of active-passive sensing fusion mechanism and device structure,the two core functional structures of sensing layer and conductive electrode layer are studied.Through key process parameters extraction and optimization,the hot steaming and alternating vacuum infiltration-annealing based-heterogeneous integrated manufacturing technology for stretchable micro-nano sensing functional materials is proposed,making the implementation of stretchable multi-sensing micro-nano sensor for multi-parameter fusion sensing.Through electrical performance characterization and test analysis of detection range,sensitivity,linearity,and repeatability,combined with the optimization of the micro-nano cross-scale structure,the organic fusion of passive and active sensing mechanisms has been realized,and a stretchable micro-nano integrated sensor with multi-sensing(stress-strain,temperature,joint motion,etc.)has been verified.It demonstrates its important potential to effectively extract multiple environmental parameters/human physiological characteristics and convert them into electrical signals,providing multi-modal information sensing for the wearing subject in a wearable scenario.The single/hybrid mechanism based-smart microsystems integrated sensing and energy supply are developed by integrating the above-mentioned micro-nano energy harvesters with multi-functional sensors.Based on an in-depth analysis of the singular quantitative correlation between external excitation and electrical output of micro-nano energy,a single mechanism based-active sensing and energy supply fusion technology is proposed.And a flexible self-powered sensing microsystem prototype integrated sensing and energy supply is realized,i.e.,a self-powered stretchable password keyboard and its integrated microsystem.Further,through an in-depth study of hybrid energy conversion mechanism and active-passive hybrid sensing mechanism,a hybrid mechanism-based sensing and energy supply fusion technology is proposed,and a prototype of elastic hybrid smart microsystems integrated multi-sensing and microenergy is realized.The above microsystem prototype has successfully realized the integration of the functional modules of micro-nano energy harvesting,sensing,signal processing,power management,and data transmission,and its smart application has also been explored and verified with the help of artificial intelligence machine learning algorithms.In summary,taking micro-nano energy harvesting and multi-sensing integration as the core,micro-nano cross-scale elastic stretchable electronic integration manufacturing technology as the entry point,the key technology of integration of sensing and energy supply and its application in the field of smart microsystems are deeply investigated.This provides a direction to effectively solve the bottleneck problems of surface heterogeneous integration,distributed reliable energy supply,and multi-functional integration faced by the practicality of stretchable electronics.It is of great significance to promote the further development and multi-domain application of wearable electronics.