Research On Near-electric Field 3D Printing Preparation Of PVDF Composite Piezoelectric Film And Sensor

PVDF piezoelectric film has wide frequency response,good flexibility,low acoustic impedance,corrosion resistance,chemical stability,and can be used in environments with complex curved surfaces.It is widely used in sensors and other fields.The performance of PVDF piezoelectric film sensors depends on the film.The piezoelectric and piezoelectric properties of the film depend on the?phase content and orientation in the film.In this topic,the PVDF piezoelectric film and its sensor were prepared by the near-field 3D printing method,and by changing the polarity of the solvent,the printing voltage,the content of high molecular weight PVDF powder and the content of ionic salt,the printing process and ion salt on the PVDF piezoelectric film were explored the effect of?phase content and the effect of multilayer PVDF piezoelectric film on sensor performance.The experimental results show that the printing process has a significant effect on the?-phase content of the PVDF piezoelectric film.The solvent polarity and printing voltage can effectively promote the transformation of the?phase of the PVDF piezoelectric film.When the solvent is NMP and the printing voltage is 6 kV,the PVDF film has the highest?phase content and the best dielectric and piezoelectric properties;secondly,changing the PVDF content in the solvent can improve the smoothness of printing and the density of the film surface,and can increase the F???,when 761A PVDF content When it is increased to 3wt%,the?phase content of the PVDF piezoelectric film can reach the highest 34.54%;under the optimal printing process conditions,a small amount of NaCl and CaCl₂ ion salts are added,and it is found that the?-phase content in the PVDF piezoelectric film can be effectively increased and improved The performance of the PVDF piezoelectric film sensor,the higher the?-phase content,the better the performance of the sensor;when the NaCl content is 0.2wt%and the CaCl₂ content is 0.15wt%,the PVDF piezoelectric film has the highest?-phase content,and PVDF The piezoelectric constant and dielectric constant of the piezoelectric thin film reach the maximum value,and the performance of the PVDF piezoelectric thin film sensor is also optimized;finally,the prepared single layer PVDF piezoelectric thin film sensor is introduced.The series-parallel study shows that the multi-layer sensor series and parallel can effectively improve the performance of the PVDF piezoelectric film sensor.The electrical signal output peak of the two-layer series PVDF piezoelectric film sensor is 1.173 times that of the single-layer PVDF piezoelectric film.The multi-layer PVDF piezoelectric thin film sensor series is 1.700 times that of a single layer,and the sensitivity of the multi-layer PVDF piezoelectric thin film sensor series is better than the single-layer PVDF piezoelectric thin film sensor,and the stability is higher than the single-layer sensor,while the two-layer PVDF piezoelectric filmm paralleled,the output voltage of the thin film sensor is 1.536 times that of the single layer,but its stability is slightly lower than that of the single layer,which can effectively improve the application range of the PVDF piezoelectric thin film sensor.