Design And Application Study Of MWCNTs/Ecoflex Flexible Strain Sensors Based On 3D Printing

With the rapid development of science and technology,flexible strain sensors with low energy consumption and high deformation have attracted great interest of many researchers.Among them,the resistive flexible strain sensor has become a research hotspot of flexible strain sensor because of its simple structure,wide measurement range,easy miniaturization and integration.There are various processes for preparing resistive flexible strain sensors.It is found that the patterning of conductive layer can regulate the performance of resistive flexible strain sensor.In recent years,the emerging 3D printing technology can quickly and simply customize the conductive layer at room temperature.In this paper,based on the respective advantages of conductive materials and high deformation elastomers,multi-walled carbon nanotubes(MWCNTs)with non-toxic,high conductivity and low cost are combined with silicone rubber(Ecoflex)with high strain,easy to grow conductive materials and good biocompatibility.Through 3D printing technology,a flexible sensor with good performance and schema is printed.The sensor has good electrical conductivity while maintaining high strain performance.It has broad application and development prospects in wearable intelligent equipment,flexible robot and other fields.The main research contents and conclusions of this paper are summarized as follows:1.The MWCNTs were printed on the surface of Ecoflex by 3D printing to form a conductive network,and the MWCNTs/Ecoflex strain sensor was obtained by encapsulating the electrode.The influence of printing parameters on device pattern was studied,and the optimization conditions were obtained.The linear sensor fabricated by 3D printing has high strain response and good linearity.It has fast response time under rapid stimulation and excellent stability under cyclic tensile release.Five linear MWCNTs/Ecoflex flexible strain sensors are attached to the joints of five fingers.The external hardware of human-computer interaction system is composed of signal conditioning circuit,STM32 microcontroller and display module,which realizes simple gesture recognition function.The VO₂@MWCNTs/Ecoflex strain sensor was synthesized by adding VO₂ particles into MWCNTs,and the response was improved compared with the sensor without mixed VO₂ particles.Due to the phase change of VO₂ near 63.8°C,the resistance decreases sharply.Combined with the single-chip microcomputer system,the temperature reminding is simply realized.2.The linear MWCNTs/Ecoflex was woven into 2×2 and 3×3 grid flexible sensors,which can realize strain sensing with positioning function.The system is composed of flexible grid sensor,signal conditioning circuit,STM32 microcontroller and display module.The visualization of positioning is realized.