Transfer Function of Interfacial Stress Sensor for Artificial Skin Applications

To help improve the comfort of an amputee, it is important to develop artificial skin to understand the load distribution between the residual limb and the prosthetic socket for a prosthetic socket system. This paper presents an interfacial stress sensor which is capable of simultaneously measuring normal compressive stress and horizontal shear stress and is expected to create an artificial skin to understand such load distribution. A mathematical model based on regression analysis is built and an experiment is conducted to obtain the transfer function of the sensor. A significance test shows that the transfer function has a statistical significance at a significance level of 0.05 and the regression model fits the experimental data with a sample determination coefficient (R²)> 0.95. The relative error is also analyzed in the end. The results show that the sensor is capable of measuring a range 0–320 kPa normal compressive stress with a relative error of 5% and a range of 0–70 kPa horizontal shear stress with a relative error of 14%.