Whisker-like sensors with tunable follicle sinus complex for underwater applications

Abstract

In this study we present the design, analysis, and experimental validation of a tunable follicle-sinus complex (FSC) unit for whisker-like sensors. The tunable FSC unit displays variable viscoelasticity enabled by a dielectric elastomer (DE) mechanism. Our previous studies on whisker-like sensors for underwater applications have shown the dependence between both static and dynamic sensor performance and FSC material properties. Variations in FSC modulus and viscosity affect its effective stiffness and damping and in turn the sensitivity and range of the sensors. A new FSC design is presented that uses a DE mechanism to tune the effective stiffness and damping of the follicle region. A model to better predict the resulting sensitivity and measurement range is described. The model accounts for the viscoelastic of the FSC components, pre-loading of the FSK volume, and stiffness ratios between the sensor whisker-like shaft and the FSC region. The changes in both the stiffness and damping of the whisker-like sensors are characterized experimentally using loading and impulse tests and compared with model estimates.