Parametric control of Poisson’s ratio in polydimethylsiloxane (PDMS) based re-entrant auxetic structures for stretchable devices application

Auxetic structures have significant potential for stretchable devices, such as flexible displays, circuits, and sensors, due to their remarkable self-deformation characteristics. However, in practical embedded systems, the mechanical response is governed not solely by the auxetic structure (AS). The mechanical behavior mismatch due to the interaction between the AS and the surrounding matrix can degrade the desired auxetic effect. Therefore, this study proposes an effective methodology to investigate a matrix-embedded Re-entrant Auxetic Cellular Structure (RACS) design, focusing on the parametric influence of key geometrical factors to achieve the desired and controlled mechanical performance for stretchable devices. A comprehensive parametric analysis, using single-unit RACS and multiple-cell RACS array configurations, is performed through simulation and experimental comparison. The results identify horizontal rib thickness as the dominant design parameter significantly affecting Poisson’s ratio, while other geometric parameters contribute comparatively minor effects. The findings provide a practical design strategy for tailoring AS in matrix-embedded systems, addressing scalability challenges and advancing their applicability in next-generation flexible devices.