Research on somatosensory shock wave pressure measurement method based on PVDF film

Abstract

Piezoelectric pressure sensors and human tissue have different pressure impedance coefficients, which results in a discrepancy when accurately measuring the real somatosensory shock wave pressure (SSWP). The aim of this research is to develop a method that can realistically characterize SSWP measurements. To achieve this, the study uses the finite element method to analyze the response of both human tissue and piezoelectric pressure sensors to the same shock wave load. The numerical simulation results show a significant difference in the pressure response between the two under identical shock wave loads. Based on this, the working mode and equivalent model of Polyvinylidene fluoride (PVDF) film for measuring SSWP are determined. Using the finite element method, the same shock wave pressure load is applied to PVDF films with thicknesses of 20 μm, 50 μm, 100 μm, as well as human tissue. The results reveal a good agreement between the pressure response of the PVDF film and human tissue. As the thickness of the PVDF film decreases, particularly at 20 μm thickness, the accuracy improves. Additionally, a comparative experiment is conducted using a bionic dummy model. The outcomes indicate that PVDF film is more stable than piezoelectric pressure sensors and can accurately characterize the real SSWP, aligning with the numerical simulation results by up to 98.4%.