Flexible Electronics On One-dimensional Metallic Silver Nanostructure

Since humans entered the electronic information age,the pace of development of science and technology has been beyond the imagination of people.The advancement of electronic science and technology in the last 20 years has brought about earth-shaking changes in the production and life of humans.However,with increasing reliance on mobile devices and raising demands for new wearable electronics,the silicon-based rigid electronics industry faces unprecedented challenges.Almost all the electronic components in the conventional rigid silicon electronic products are rigid,it can be expected that this kind of rigid electronic equipment will be increasingly difficult in the future to meet the needs of the work and life of people.At this time,versatile electronics,regarded as the base of the next generation of electronic industry,received a lot of attention.Flexible electrons demonstrate remarkable mechanical strength,lightweight,and portability compared to conventional rigid electrons based on silicon or conductive oxides.Scientists have developed and prepared various flexible nanostructures to create high performance flexible electronic devices.Due to its inherent mechanical strength,large specific surface area,bidirectionally restricted domain structure and special photoelectric characteristics,one-dimensional metallic silver has attracted considerable attention among them.Though one-dimensional metallic silver preparation methods have emerged one after another,production methods with real high performance,high quality and promising industrial application are still much needed and awaited.This study is based on the development of a new preparation process with industrial production potential and comprehensive application prospects to achieve macro-preparation and large-scale application of high-quality one-dimensional silver metal materials.Main works are as follows:1.We develop a roll-to-roll(R2R)process for the fabrication of flexible,extra-large,transparent AgNF network electrode.By combining R2R blow spinning with simultaneous ultraviolet(UV)irradiation,we have successfully assembled a roll of transparent AgNF/PET electrode.The entire fabrication process was performed at room temperature and atmospheric pressure without any harsh chemical reaction.The optical and mechanical properties as well as the electrical conductivity of our products are comparable with those AgNF network assembled via high-temperature sintering.The as-prepared AgNF network was then assembled into a flexible A4-sized ECSW,presenting better property than that of a commercial ITO-based device.This method provides the possibility of applying transparent AgNF network electrode in flexible and extra-large electronic equipment,such as nonplanar ECSWs and curved surface displays.2.We propose large-scale application strategy of AgNWs/polyvinyl butyral(AgNWs/PVB)low emissivity(Low-E)coating materials.By a facile spraying process,this coating material can be closely attached to the common glass,forming Low-E glass.The spraying process is flexible and can be performed by manual operation and/or an automatic continuous R2R process.In contrast to existing vacuum sputtering techniques,such an R2R process can effectively avoid many complications such as the need for a vacuum environment,preprocessing,and a limited range.The AgNWs/PVB coating showed high transmittance of visible light(?83.0%),high reflectivity of mid-IR(?69.8%),low emissivity,as well as reliable chemical and mechanical durability.3.By fine regulation of the blow spinning parameters,we successfully prepared a large aspect ratio silver fiber with a diameter of about 650 nm and a length more than 10 cm.We further deposited the silver fiber on PET transparent plastic substrate at room temperature to make a thin film material that can be used for electromagnetic shielding on transparent surfaces.Due to its low duty factor and adaptive fiber diameter,the material achieves high visible light transmittance while the monolayer thickness of the fiber is greater than the skin depth of metallic silver,ensuring an excellent electromagnetic shielding performance of it.4.The most advantageous 3D networked strategy of X-band electromagnetic shielding based on one-dimensional metallic silver is studied by simulation.Based on this result,we fabricated a highly robust AgNWs/PVB melamine sponge EMI shielding material using an R2R method.The accessory polymer,PVB,acts as both the structural reinforcement,antioxidant and waterproof coating to insure the proper functioning of this material under different environment.EMI shielding tests with a vector network analyzer show 60 dB EMI SE for as-prepared material with a thickness of 0.5 cm.This value is higher than for commercial Ni-coated commercial EMI shielding sponges of the same thickness.Moreover,this material reveals excellent mechanical due to its primary elastic skeleton structure,and good chemical stability,which enables large-scale EMI shielding applications in the future.5.We report a flexible,robust,cost-effective,mass-produced,and gel-free silver-nanowire/PVB/melamine sponge electrode for next generation noninvasive brain-computer interface(BCI).Benefit from its flexibility and skeleton structure,the electrode could effectively bypass part of the hair of the subjects to achieve direct contact with the scalp,no matter in the subjects with long or short hair.In addition,after surface modification and introduction of additives,the electrode exhibits excellent chemical and mechanical stability.The BCI performance measurements on hairless skin show that the accuracy of the new electrode(86%)is approximately the same as that of conventional electrodes supported by conductive gel(88%).Most importantly,the performance of the new electrode on hairy skin is not significantly reduced,which shows that the hair blocking problem is effectively solved.