A highly tunable silicone-based magnetic elastomer with nanoscale homogeneity

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:324

Article

Evans, Emily A.¹  Fiser, Briana L.²  Prins, Willem J.¹  Rapp, Daniel J.¹  Shields, Adam R.³  Glass, Daniel R.¹  Superfine, R.² 

[1] Elon Univ, Dept Phys, CB 2625, Elon, NC 27244 USA

[2] Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA

[3] USN, Res Lab, Ctr Bio Mol Sci & Engn, Washington, DC 20375 USA

关键词: Magnetic polymer;    PDMS;    Composite material;    Magnetic nanoparticle;    Actuator;    Microelectromechanical system;   

DOI  :  10.1016/j.jmmm.2011.08.045

来源: Elsevier

【 摘 要 】

Magnetic elastomers have been widely pursued for sensing and actuation applications. Silicone-based magnetic elastomers have a number of advantages over other materials such as hydrogels, but aggregation of magnetic nanoparticles within silicones is difficult to prevent. Aggregation inherently limits the minimum size of fabricated structures and leads to non-uniform response from structure to structure. We have developed a novel material that is a complex of a silicone polymer (polydimethyl-siloxane-co-aminopropylmethylsiloxane) adsorbed onto the surface of magnetite (gamma-Fe2O3) nanoparticles 7-10 nm in diameter. The material is homogenous at very small length scales (< 100 nm) and can be crosslinked to form a flexible magnetic material, which is ideally suited for the fabrication of micro-to nanoscale magnetic actuators. The loading fraction of magnetic nanoparticles in the composite can be varied smoothly from 0 to 50 wt% without loss of homogeneity, providing a simple mechanism for tuning actuator response. We evaluate the material properties of the composite across a range of nanoparticle loading, and demonstrate a magnetic-field-induced increase in compressive modulus as high as 300%. Furthermore, we implement a strategy for predicting the optimal nanoparticle loading for magnetic actuation applications, and show that our predictions correlate well with experimental findings. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

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