Characterization of Magnetoactive Elastomers as Actuators of Bi-stable Composites
Open Access
- Author:
- Iatesta, Ethan
- Area of Honors:
- Mechanical Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Zoubeida Ounaies, Thesis Supervisor
Daniel Humberto Cortes Correales, Thesis Honors Advisor
Jose Pinto Duarte, Thesis Supervisor - Keywords:
- Bistable
Laminate
Composite
magnetoactive
elastomer
MAE
Actuation
Responsive
Architecture
facade
Active Material
Magnetic - Abstract:
- Smart materials are the technology of choice for researchers and designers who seek to add functionality and adaptability to building envelopes. These smart materials create a theoretical framework for the design of environmentally responsive architectural systems. For example, buildings can be designed with enhanced functionality to dynamically adjust to weather conditions, which could save energy and improve interior comfort. This study proposes a kinetic building façade consisting of bistable laminate sheets actuated by magnetoactive elastomers (MAE), which switch the sheets from one stable configuration to another to regulate lighting and increase building efficiency. These laminate sheets exhibit the property of bistability, where two states of equilibrium are possible, each of which is natural and stable; therefore, the structure can settle at either equilibrium without needing any external forcing. This specific study utilizes magnetoactive (MAE) polymer-based actuators that force the bistable laminates from one stable configuration to another. The MAEs in this study are made of poly(vinyl alcohol) (PVA) polymers and poly(dimethylsiloxane) (PDMS) elastomers as the matrix materials and iron oxide particles as the magneto responsive inclusions. When a magnetic field is applied to the MAEs, the soft-magnetic particles within the polymer matrix are attracted to and align with the applied magnetic field. The interaction between the magnetic particles results in bending and straining of the polymer composites and creates large deformations in the MAE samples. This bending motion is exploited to actuate the bistable laminate sheets. In order to understand the behavior, capabilities, and limitations of MAEs as actuators of bistable laminates, quantitative data concerning the displacement and force potential of both PVA and PDMS MAEs is collected. The goal is to assess the effect of the MAE type, placement and testing procedures for future MAE and bistable laminate actuation. These findings are utilized in the actuation of bistable laminates using permanent magnets. Finally, the clamped boundary condition of bistable laminates is explored to achieve lower actuation forces that would be advantageous in any active building façade system. Through experimentation, the relationship between type, location and testing parameters was investigated to determine the minimal force needed for bistable laminate actuation. The resulting trends and parameters can be used to predict further improvement in the actuation of bistable laminates and their eventual utilization as the active material in a responsive architectural system.