| Artificial intelligence robots mainly rely on a variety of sensors to perceive and analyze the environment,thus possessing similar or beyond human senses to respond to the external environment.Therefore,the root cause of artificial intelligence is the product of the continuous development of various sensors.Tactile sensor is one of the core components of artificial intelligence robot to obtain bionic tactile sensation function,and its development and progress are extremely important for the construction of artificial intelligence robot.In recent years,under the traction of demand,various types of tactile sensors have made great progress through the design of various exquisite strategies of research workers.However,in order to obtain skinlike sensing,tactile sensors need to be flexible,flexible,waterproof,breathable,highperformance,low-cost,and can be integrated in large quantities,which poses great challenges to the selection,design and synthesis of materials and the preparation technology of devices.In this paper,a series of studies are mainly carried out to solve the above problems,and the main contents are as follows:1.Aiming at the problems of waterproof,breathable,flexible,fitting and wearing comfort of the tactile sensor,PVDF with natural hydrophobic characteristic was selected as the precursor of active material,and a β-PVDF nanofiber membrane(NM)with porous structure was obtained by advanced electrospinning process.Because strong mechanical stretching and high-voltage electric field can act on each fiber of the nanofiber membrane in the electrospinning process,the polarization degree of the material was enhanced,and then the piezoelectric characteristics of the material were strengthened,thus obtaining a nanofiber interconnected permeable membrane with high-voltage electrical characteristics.In order to solve the problems of waterproof,breathable,flexible,fitting and wearing comfort of tactile sensor,PVDF with natural hydrophobic characteristics was selected as the precursor of active material,and β-PVDF nanofiber membrane(NM)with porous structure was obtained by advanced electrospinning process.Because strong mechanical tension and high-voltage electric field can act on each fiber of the nanofiber membrane during electrospinning,the polarization degree is enhanced,and then the piezoelectric characteristics of the material are strengthened,thus obtaining a nanofiber interconnected permeable film with high-voltage electrical characteristics.The natural hydrophobicity of the material,combined with tens of thousands of micropores in PVDF NM,makes the constructed sensor have excellent waterproof,air permeability and full flexibility,and can easily fit and wear comfortably.2.In order to construct a tactile sensor with high sensitivity,low detection limit,good stability and rapid response/recovery ratio,under the guidance of piezotronics,we take the above-mentioned β-PVDF NM with electromechanical conversion function as the signal input end and the flexible organic field effect transistor(OFET)device with signal amplification function as the signal output end,and construct a pressure sensor through capacitive coupling.The sensor not only has excellent pressure sensitivity,detection limit and response time,but also has good fitting,waterproof and breathable functions.More interestingly,the charge generated by PVDF NM polarized by piezoelectric effect is enough to drive OFET device,which still shows good sensing performance in monitoring human physiological signals without applying gate voltage.3.In order to get closer to skin-like sensing,we explored the breathable multifunctional tactile sensor based on carbonized PVDF skeleton.After defluorination,crosslinking and carbonization,the permeability of the three-dimensional porous membrane of PVDF NM was retained,and it was used as a pyrrole with the characteristics of detecting various signals on the skeleton load to prepare a multifunctional tactile sensor with the characteristics of detecting various stimulus signals.The carbonized PVDF NM three-dimensional breathable skeleton can directly initiate pyrrole polymerization on its surface by solution immersion,which simplifies the operation steps.At the same time,the diameter of the fiber is nanometer,and the morphology is regular,and polypyrrole can completely coat the surface of the nanofiber.The method is simple and feasible,and the obtained materials are expected to achieve better development in the fields of electronic skin,artificial intelligence,wearability and health monitoring. |
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