Magnetorheological materials

Magnetorheological materials (fluids) are the magnetic equivalent of electrorheological fluids. In this case, the particles are either ferromagnetic or ferrimagnetic sohds that are either dispersed or suspended within a Hquid and the apphed field is magnetic (14). 

Jon, R., Suresh, G., and Natrajan, V., Studies on magnetostrictive properties of a magnetorheological elastomer. Proceedings of ISSS International Conference on Smart Materials, Structures and Systems, Bangalore, India, July 28-30, 2005, SA-122. 

Magnetorheological (MR) materials, 22 708t, 714-715, 721t Magnetostriction effect, in ferrites, 11 62-64... 

University of Alberta. Educational Software for Micromachines and Related Technologies. Available online. URL http //www. cs.ualberta.ca/ database/MEMS/sma mems/index2.html. Accessed May 28,2009. Research groups at the University of Alberta in Canada constructed this Web resource, which discusses a variety of smart materials, including shape-memory alloys, piezoelectric materials, and electrorheological and magnetorheological fluids. 

National Aeronautics and Space Administration—Ames Education Division Smart Materials. Available online. URL http //virtualskies.arc. nasa.gov/research/youDecide/smartMaterials.html. Accessed May 28, 2009. As part of an educational activity in which students plan an aviation research project, this Web site provides links to pages discussing piezoelectric materials, electrorheological and magnetorheological fluids, shape-memory alloys, and magnetostrictive materials. 

So far, applications for electrorheological and magnetorheological liquids are rather limited in number, but researchers predict that they will eventually find a number of applications in industry, aerospace, the military, and other fields. As with other fields of materials science, much more basic research is needed to understand the behavior of electrorheological and magnetorheological liquids before everyday applications can be developed. 

Materials that allow an intelligent or smart structure to adapt to its environment are known as actuators. These materials have the ability to change the shape, stiffness, position, natural frequency, damping, friction, fluid flow rate, and other mechanical characteristics of adaptronic structures in response to changes in temperature, electric field, or magnetic field. The most common actuator materials are shape memory alloys, piezoelectric materials, mag-netostrictive materials, electrorheological fluids, and magnetorheological fluids [2]. Actuators with these materials will be described in detail in Sects. 6.2 to 6.6 therefore you will find only a brief overview below. 

The characteristics of magnetostrictive and magnetorheological actuators indicate hysteretic and nonlinear behaviour as well. In contrast to piezo actuators, where properties of the material dominate the operating behaviour, the hysteresis of these actuators is influenced also by design features (partly... 

Kordonsky, W. Magnetorheological Effect as a Base of New Devices and Technologies. J. Magnetics and Magnetic Materials 122 (1993), pp. 395-398... 

Carlson, J.D. Matthis, W. Toscano, J.R. Smart Prosthetic Based On Magnetorheological Fluids, Industrial and Commercial Applications of Smart Structures Technologies. Proc. SPIE 8th Aimual Symp. on Smart Structures and Materials, Newport Beach, 2001 March 5-8, 4332 (2001), pp. 308-316 Biedermann, L. Int. Patent Appl. W09929272A1 (1999)... 

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