Proceedings Article | 9 May 2024
KEYWORDS: Electrodes, Sensors, Capacitance, Design, Manufacturing, Dielectrics, Carbon, Deformation, Capacitors
Flexible and stretchable electronics have garnered significant interest for their potential applications in fields like soft robotics, sensor-integrating machine elements, Industry 4.0, biomechanics, and wearable technology. Among these innovations, multi-layer capacitive strain sensors based on dielectric elastomers (DEs) stand out for their sensitivity, large deformation range, and compatibility with complex shapes. In this study, the focus is on advancing the design, fabrication, and evaluation of multi-layer capacitive strain sensors based on DEs. The goal is to explore novel approaches to enhance stability, sensitivity, and manufacturability. The research in this work introduces a comprehensive classification of four-electrode layer DES (4EL-DES) structures, including a new 50 μm-C configuration, to identify designs maximizing capacitance and sensitivity. Additionally, investigation into electrode pin designs is conducted which considers manufacturing feasibility and mechanical stability, utilizing finite element (FE) simulations and experimental validation to assess various options. Novel fabrication techniques, such as upside-down electrode layering and the use of conductive thread paired with conductive carbon grease for electrode connections, aim to streamline manufacturing and enhance reliability. FEM simulations analyze stacked 4EL-DES structures’ deformation behavior and the relationship between capacitance change and strain, providing insights into their mechanical and electrical properties under different loading conditions. Experimental results from various sensor configurations, including individual 4EL-DES sensors and stacked and "open" 5EL-DES structures, offer insights into performance capabilities and potential applications. This research contributes to advancing flexible sensor technology, laying the groundwork for high-performance sensors applicable in soft robotics, biomechanics, and beyond.
