June 16, 2002
June 16, 2002
June 19, 2002
7.1004.1 - 7.1004.3
John A. Marshall, PHD University of Southern Maine
Smart Materials represent a relative new branch of material science that is comprised of materials that respond with a change in shape or state upon application of externally supplied driving forces. These materials often carry titles as Intelligent Materials, Active Materials, or Adaptive Materials.
Many of these materials, such as shape memory alloys, develop enough usable force during their shape change to power small linear actuators and motors. Conversely, some of these materials can also be used as sensors where a strain applied on the material is transformed into a signal that allows computation of the strain levels in the system.
Rather than exhibiting a shape change, other smart materials demonstrate unique properties such as change of state. Electro- and magneto-rheological fluids, for example, can change viscosity over many orders of magnitude upon application of an external magnetic or electric field. This change of state has the potential to revolutionize the control aspects and responsiveness of hydraulic power transmission.
The purpose of this presentation will be to provide a method of classification for these smart materials, and to also provide an update on recent and new applications. In addition, a smart materials (magneto-rheological fluid) will be demonstrated in the context of experiments suitable for classroom instruction. Perquisite knowledge in the form of elementary power transmission concepts would be helpful but not required, and this activity is suitable for any level participant.
Magneto-rheological fluid is a smart material that changes its flow characteristics when subjected to an electrical field. Response, which takes only milliseconds, is in the form of a progressive gelling that is proportional to field strength. With no field present, the fluid flows as freely as hydraulic oil (Korane, 1991).
Magneto-rheological fluids represent a technology that has the potential to widen the performance range of automated electromechanical and electrohydraulic equipment. Research and ongoing developments are refining this active material and experts predict an important future for these smart materials.
“Proceedings of the 2002 American Society for Engineering Education Annual Conference & Exposition Copyright 2002, American Society for Engineering Education
Marshall, J. (2002, June), Smart Materials Paper presented at 2002 Annual Conference, Montreal, Canada. 10.18260/1-2--10938
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