Study of the actuation behaviour of magnet-polymer morphing composites

• Main Author: Lee, Wilson Kah How
• Other Authors: Raju Vijayaraghavan Ramanujan
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials::Magnetic materials
• Online Access: http://hdl.handle.net/10356/60169
• Institution: Nanyang Technological University

Magnetic-polymer matrix composites (MagPol) have recently gained interest in the field of actuators due to some of its properties which include exhibiting high strain levels, different actuation modes and the ability to respond reversibly to a magnetic field in an effective manner. For this project, Mn0.7Zn0.3 Fe2O4 and Mn0.8Zn0.2 Fe2O4 nanoparticles were prepared using co-precipitation methods and hydrothermal synthesis. MagPol films were synthesized with ethylene-vinyl acetate (EVA) as the polymer matrix and the magnetic nanoparticles as the filler. The magneto mechanical and static actuating properties of the composite films were characterized. Force, stress, strain and work produced by the composite films were some of the factors studied in detail. All films displayed superparamagnetic behaviour. Experiments showed that increasing the filler loading levels also led to higher saturation magnetization. The films were also shown to be able to display high levels of strain in the presence of a static magnetic field. By increasing the filler loading levels of magnetic nanoparticles, higher strain can be obtained. Saturation magnetization and filler loading levels shared a linear relationship. A logarithmic relationship is observed between the saturation magnetization and the filler loading levels. Work generated for the magnet-polymer nanocomposite films was calculated using the Work-Loop method. Increasing filler loading levels led to more force produced and a higher work/work density performance. MnxZn1-xFe2O4 nanoparticles/EVA nanocomposites films possess good work density capacity in relation to their weight. In addition to displaying high strain levels, the films are a good choice for the development of morphing and actuator technology. Combining MagPol with other actuation technologies such as electroactive/conductive polymers, can lead to better performance in certain applications.