Magnetic actuation of bistable flaps for kinetic building shades

• Published in: Construction & building materials Vol. 392; p. 132028
• Main Authors: Vazquez, Elena, Ounaies, Zoubeida, Iatesta, Ethan, Duarte, Jose
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.08.2023
• Subjects: Adaptive screens; architectural technology; arkitekturteknik; Bistable laminates; Kinetic architecture; Magnetoactive elastomers (MAEs); Bistable laminates; Kinetic architecture; Magnetoactive elastomers (MAEs); Adaptive screens
• ISSN: 0950-0618; 1879-0526; 1879-0526
• DOI: 10.1016/j.conbuildmat.2023.132028

•Magneto-active elastomers (MAEs) are characterized as actuators for bistable kinetic shadings.•Two different polymer matrices are tested for MAEs—polyvinyl alcohol (PVA) and polydimethylsiloxane (PDMS) —to determine their suitability for the intended application.•Increasing the clamped height can drastically reduce the magnetic field required for actuation. Kinetic building envelopes can significantly improve energy efficiency by adapting to changing outdoor conditions. A challenge for the widespread implementation of kinetic envelopes is related to the complexity and cost of conventional mechanical actuation. Current trends in kinetic building design have proposed embedding smart materials for actuation within kinetic shades and simplifying the shape-morphing mechanisms. This paper reports on a study that aims to characterize magneto-active elastomers (MAEs) as actuators for bistable kinetic shadings. In particular, this study seeks to determine adequate bistable and MAE configurations and their potential to deform a bistable kinetic shading setup. The studies characterize the force and displacement of two types of MAEs materials fabricated by embedding magnetic fillers into different soft polymeric matrices- polydimethylsiloxane (PDMS) and polyvinyl alcohol (PVA) hydrogel. In addition, we compared the actuation capabilities of both MAE-PDMS and MAE-PVA and studied the effect of changing the boundary condition of bistable laminates. The results suggest that MAE materials can actuate bistable composites remotely. The boundary condition study found that clamping 25% of the laminates' height reduced the magnetic field required for actuation by 29% and thus might be a suitable design strategy. This study adds magnetic actuation to the growing body of work on kinetic envelopes and smart materials, contributing to a deeper understanding of the required application conditions of MAEs.