Multi-layer Electrical Impedance Tomography Based Soft Tactile Skins

Distributed high-density tactile sensing is a challenging problem with numerous commercial applications. Soft sensing technologies appear to be a promising approach to address this challenge. In particular, Electrical Impedance Tomography (EIT)-based soft sensors are desirable because they can offer a large sensing surface without rigid electrodes and provide high sensing resolution. However, their applicability is limited to simple sensor shapes, and they require materials with high conductivity for sensing accuracy. This project introduces a novel multi-layered architecture for EIT-based soft skins. This innovation allows us to develop sensory skins with multiple materials and provides greater flexibility in electrode placement, resulting in higher accuracy. We experimentally tested the method's applicability using soft skins of varying morphology, employing a hydrogel-based tactile skin. The results demonstrate that our multi-layer soft skin improves average accuracy compared to a single-layer EIT-based skin, reducing it from 15.8 mm to 4.4 mm.