Integration And Performance Of Flexible Bionic Sensing Devices

With the development of science and technology,flexibility,miniaturization,integratability and multi-functionalization are the major developing trends for future bionic electronic devices.It requires higher demands towards the device structure and performance of bionic electronic devices.Therefore,it is urgent to exploit novel device structure,sensitive mechanism and new application field to meet the requirements of bionic electronic devices.In this thesis,we focus our research issues on flexible electronic skin and artificial visual memory system with high performance,in order to mimic human skin and visual system.Firstly,a highly stretchable conductive fiber with high conductivity,good stability,and excellent flexibility is developed based on the polymer nanofibers mat and silver nanowires layer.The superior features have made it possible to monitor vigorous motions(finger bending or stretching)and subtle physiological signals(pulse and phonation)precisely.The fiber-based strain sensor exhibits high gauge factor of 5.326,rapid response of 20 ms,and outstanding durability after 10000 strain cycles.The smart data glove integrated with ten-channel circuit in each joint of fingers can recognize various gestures in real time by detecting the motions of fingers.Then,a self-assembled network platform that combines natural viscoelastic polymer nanofibers with conductive graphene is fabricated to assemble the piezoresistive pressure sensor.Moreover,ultrathin and flexible E-skin sensor with multimodal sensing capability is prepared.The effective amplification and transformation of various external stimuli to independent electrical signals enables the precise and continuous sensing of pressure and temperature.High pressure sensitivity of 31.6 kPa-1 and accurate temperature resolution of 0.08 ?-1 are obtained.This work provides the technological verify between structure of materials and properties of device and make hollow materials possess promising application in E-skin and health-monitoring elements.For the mimicry of human visual memory,a facile architecture to construct artificial flexible visual memory system by employing ultraviolet-motivated memristor is designed.The resistance switching of image sensors by sensing applied light can be recorded in the nonvolatile memory devices,thus realizing the detection and memory capacities toward light as human visual memory.The visual memory arrays(10×10 pixels)can realize the detection and memory process of ultraviolet light distribution with patterned image for a long-term retention(>one week).These results provided new opportunities for the mimicry of human visual memory and enable the flexible visual memory device to be applied in future wearable electronics,electronic eyes,multifunctional robotics and auxiliary equipment for visual handicapped,etc.