Arrays of micro-electrodes and electromagnets for processing of electro-magneto-elastic multifunctional composite materials

Boyd, James G.; Lagoudas, Dimitris C.; Seo, Cheongsoo

doi:10.1117/12.483590

Cited by 8 publications

(3 citation statements)

References 4 publications

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“…Potential applications include low-loss cores in power transformers [1], electromagnetic shielding [2,3], microelectromechanical systems (MEMS) magnetic sensors or actuators [4][5][6][7][8][9] and selective thermal actuation of shape memory polymers in medical devices [10]. They have tunable electromagnetic properties (such as index of refraction and RF absorption), may be heat-activated to self heal (via hysteresis or magnetic relaxation losses in alternating external magnetic field) and can be used for selective, remote thermal actuation.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Nickel Nanowire Polymer Composites

2006

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Magnetic polymers are multi-functional composites emerging as a new category of smart materials. This work focuses on fabrication and characterization of magnetic polymer nanocomposites based on polydimethylsiloxane (PDMS) elastomer matrix. The magnetic fillers are commercially available Ni nanoparticles and respectively in-house fabricated Ni nanowires. Synthesis of Ni nanowires is achieved by electroless deposition inside nanoporous anodic alumina templates. After template removal, the nanowires are coated with 1-Octodecanethiol surfactant and mixed with PDMS using a FlackTek SpeedMixer TM . In parallel, nanoparticles are mixed with PDMS, without undergoing surfactant coating. Both composites are evaluated by scanning electron microscope (SEM) to determine dispersion uniformity. Mechanical properties are resolved by tensile tests performed by an instron. Preliminary results suggest that surfactant addition enhances dispersion, while mechanical properties of the composites for up to 5 vol. % of added nickel remain close to that of the polymer matrix without filler.

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Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Nickel Nanowire Polymer Composites

2006

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“…Boyd et al [3] presented a method for using arrays of microelectro-mechanical systems electrodes and electromagnets to achieve micro scale positioning of piezoelectric and piezomagnetic particles in liquid polymers, which would then be solidified to make a polymer matrix magneto-electric composite. This ability would reduce concentrations of stress, electric field, and magnetic field, thereby increasing effective threshold properties such as strength, electric breakdown field, and magnetic saturation field.…”

Section: Introductionmentioning

confidence: 99%

Study on Electro-Magneto-Elastic Fiber Composites with Periodically Distributed Reinforced Phases Under Antiplane Deformation Mode and its Applications

Xing-li¹,

Hou²,

Xu³

2011

TOMSJ

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Abstract:The response of electro-magneto-elastic long fiber composites containing periodically distributed reinforced phases under antiplane shear load coupled with inplane electromagnetic load, which lead to the antiplane deformation mode, is dealt with. There are three different electro-magneto-elastic materials in the unit cell (3-phase model), a rigorous analytical method is developed by using the generalized eigenstrains concept integrated with the doubly quasiperiodic Riemann boundary value problem theory. The expressions of electro-magneto-elastic fields in each phase of composites are obtained. As an important application of the presented solution, the effective electro-magneto-elastic moduli are predicted by using the average field theorem and compared with the results derived from the generalized self-consistent method.

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“…The use of FEM simulations for electromechanical or magnetomechanical systems has been mostly used in MEMS designs [143][144][145][146], e.g., magnetic MEMS beams.…”

Section: Finite Element Methods For Electromagnetic Computationmentioning

confidence: 99%

Magnet-polymer composite transducers

Nguyễn¹

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Current actuation technologies do not provide a satisfactory solution to the requirement of having a muscle like motion, such motion will be very useful in robotics, MEMS and biomedical applications, etc. Hence a magnetically actuated material was studied as an "artificial muscle". The material is a composite of a soft polymer with magnetic material as the filler (Magpol). Magpol composites are a new class of bio-inspired smart soft transducers for morphing, damping, and artificial muscle applications. Magpol exhibits large changes in shape and physical properties in response to an external magnetic field. This shape changing behavior of Magpol in an external magnetic field was studied and actuation performance investigated. The large change in electrical resistivity driven by the shape change was also examined for sensing applications. This versatile combination of actuation and sensing behavior results in attractive transducers. Various actuation modes, including contraction, elongation and deflection were studied. These actuation modes can be combined to produce complex motions. A novel coiling mode was observed. Simply by changing boundary conditions, Magpol can exhibit a change in actuation mode from axial contraction to a novel coiling mechanism. The magnetic buckling which results in coiling was studied by computer simulation and analytical modeling. The analytically predicted magnetic fields for buckling agreed well with experimental values. The relationship between strain and magnetic field suggested that post buckling behavior is a stable symmetric bifurcation, which is useful for continuous actuation. The actuation metrics of Magpol were studied, maximum strains were 40% for contraction, 60% for coiling and 80% for elongation. Maximum stress of up to 164 kPa, 184 kPa and 216 kPa were measured in contraction, coiling and elongation modes, respectively. These metrics are equal or better than those in natural muscles and most competing artificial muscle technologies. This thesis also presents the first report of work-loop measurement for this class of smart material. The maximum measured work values were 141 kJ/m 3 for contraction and 164 kJ/m 3 for coiling. The maximum work density of Magpol was higher than the maximum work density of mammalian iii skeletal muscles. A proof-of-concept artificial muscle made from Magpol was demonstrated. Experiments on the dynamic properties showed that Magpol can achieve a strain rate of more than 1500 %.s-1 and respond to a driving frequency of up to 80 Hz. A strain-time model showed that the dynamic properties could be related to its unique "on-off" actuation behavior. Percolation principles can be used to make this type of actuator an intrinsic self-sensor. The electrical resistivity of a polymer matrix containing fillers of iron particles and graphite flakes at percolation concentration is a strong function of mechanical strain and thus can be used for automatic sensing. Large changes in resistivity of three to four orders of magnitude and sensitivity (i.e., the chan...

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Arrays of micro-electrodes and electromagnets for processing of electro-magneto-elastic multifunctional composite materials

Cited by 8 publications

References 4 publications

Fabrication and Characterization of Nickel Nanowire Polymer Composites

Fabrication and Characterization of Nickel Nanowire Polymer Composites

Study on Electro-Magneto-Elastic Fiber Composites with Periodically Distributed Reinforced Phases Under Antiplane Deformation Mode and its Applications

Magnet-polymer composite transducers

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