As the application of fibre reinforced polymer composites (FRP) becomes more widespread there is a desire to add functionality beyond that of simple mechanical properties in order to facilitate the development of 'smart' materials. For example, the functionality being discussed in this paper is the imparting of significant magnetic properties to a FRP. This can take the form of soft magnetic performance for use in electrical machines or hard magnetic performance for novel forms of sensing or power generation. It has been demonstrated that by using hollow glass fibres as a reinforcement, magnetic material can be introduced into these fibres without significant effects on the structural behaviour of the FRP. The current studies have included the assessment of such a magnetic FRP in a variety of applications. The addition of hard magnetic materials, e.g. magnetite and barium ferrite, has been achieved through the use of nanopowders and the resulting FRP has been assessed for morphing structures applications. The magnitude of magnetic performance that can be currently achieved is controlled by the availability of suitable magnetic materials in fine powder form and the volume of magnetic material which can be incorporated within the fibres.
A major issue yet to be resolved for embedding sensors, actuators and microelectromechanical systems (MEMS) in 'smart' structures is that of providing power. Work is ongoing in the field with examples of micro battery technology, use of solar power and micro fuel cells. The work presented here considers a technology to enable the development of integrated power generation and actuation. Magnetic fibre reinforced composite material has been developed which utilises hollow glass fibres filled with active magnetic material. The resulting material maintains structural integrity as well as providing a possible means of electrical power generation from a dynamically loaded structure. The hollow glass fibres were manufactured in-house using a bespoke fibre drawing facility. Hard magnetic powder materials were introduced into the hollow fibre cores to provide an active electromagnetic function. This paper will discuss the manufacture, characterization and optimisation of active magnetic fibre reinforced composite materials.