Facile Fabrication of Soft Sensors for the Tactile Perception of Modulus

The perception of touched object softness, or modulus, is a fundamental way in which people interact with their environment. Recapitulating this ability with skin-inspired tactile sensors is vital for the advancement of robotic manipulation and the completion of highly nuanced tasks. Humans feel softness through the activation of both slow adapting (SA) I and II cutaneous mechanoreceptors, which sense pressure and strain, respectively. Typically, polymeric electronic skins, or eSkins, emulate such functionality by combining capacitive and resistive sensing components. However, existing multimodal designs are difficult to fabricate and have large spatial footprints. To overcome these challenges, we present a modulus sensor in which the top electrode of a parallel-plate capacitor is a serpentine patterned resistive strain sensor. Digitally patterned conductive carbon structures impregnated with a styrene-ethylene-butylene-styrene elastomer created robust and easily modifiable electrodes. Additionally, by having the capacitor and resistor located at the same taxel, our design may enable improved spatial density and accuracy in sensing arrays. This talk will discuss the effect of parameters – including object dimensions, materials selection, and dielectric layer structure – on the sensor output. When integrated with robotic systems or prosthetics, this biomimetic sensor has the potential to provide sophisticated sensory feedback for force modulation, safer human-robot interactions, and natural sensation on artificial limbs.