2D/3D Printing Of Electrospun Fibers And Utilization For Strain Sensing

Electrospinning is the method of preparing micro/nanofibers by stretching the solution or melt with electrostatic force.Micro/nanofibers have a large specific surface area and the surface is easily modified.The fiber membrane formed by electrospinning has characteristics such as light weight and soft texture,so it has great application on various field involved in tissue engineering,drug release,electronic components,sensors,flexible wearable devices,etc.In order to meet different application occasions,we need to assemble micro/nano fibers of different materials according to the structure or morphology required by the application.But redesigned the nozzle or receiver board of the electrostatic spinning device are main method to meet various demand for application until now.The conventional electrospinning method is mainly used for preparing disordered micro/nanofiber structures.When a drum or parallel plate is used as a receiving device,a uniaxial arrangement of micro/nano fibers can be prepared.However,the area,thickness,topography of fiber deposition on receiver cannot be effectively controlled,the application field is limited.In recent years,near-field electrospinning methods have been used to prepare micro/nanofibers with uniaxial alignment and controllable deposition,which overcomes the uncontrollability of fiber deposition in conventional electrospinning.But the distance between the nozzle and the receiving device is generally less than 3 mm on near field electrospinning process,the phenomenon of discharge and air breakdown are more possible to occur,and micro/nanofiber with uneven diameter and other defects can happen due to incomplete evaporation of the solvent.In this paper,a uniform-field electrospinning(UFES)method is proposed.a uniform electric field is formed between collector and the new spinneret made of inserting syringe to the center of the aluminum plate instead of the traditional spinneret,and is effectively prolongs the jet stabilization phase of the fiber,improves the deposition accuracy of the fiber on collector,and uses safety.Then the theoretical analysis is done by electric field simulation software,and comparing with traditional electrospinning provides a theoretical basis for the precise deposition of fibers produced by UFES.Therefore,influencing factors affecting the UFES process were studied,various two-dimensional and three-dimensional structures consisted of micro/nanofibers can be printed by UFES,as varying movement trajectory and speed of collector.When the blends solution of polyvinylidene fluoride and carbon nanotubes is used as the spinning solution,a conductive bar-shaped structure composed of bent fibers can be printed by UFES,which has the advantages of simple preparation process,flexible and stretchable,etc.,can withstand large uniaxial deformation,so it can be used as a strain sensor to monitor the flexion and extension of the finger,which has great application potential for use as a flexible and wearable device,sensor,etc.