Finite element simulation and parameter optimization of a flexible tactile pressure sensor array

Abstract

A finite element model was developed to optimize design of a flexible tactile sensor. The sensor consists of layers of thin-film copper and PDMS, and the model can be used to determine the effects on sensor sensitivity and durability of variations in material properties and geometry. The model was used to study the effect of variations in copper thickness. Four copper thicknesses, 0.3[mu]m, 0.5[mu]m, 3[mu]m, and 9[mu]m, were analyzed under a range of pressure loads. The thickness of the copper affected both the stress in the material and the displacement of the copper when a pressure load was applied to the sensor model. The stress in the sensor was highest for 3[mu]m copper, potentially causing decreased durability in this sensor. The separation between the copper strips beneath the pressure load was highest for 9[mu]m copper, so this sensor may have lower accuracy for small loads. Thin copper strips are challenging to manufacture, so the largest but most accurate and durable copper strip thickness, 0.5[mu]m, is recommended from this analysis.