Ferromagnetic microwires enabled polymer composites for sensing applications

In the present work sensing functionalities are introduced into structural composites via embedded magnetic microwires A systematic study on the structure and functionalities of microwires and their composites is performed The single-wire composite shows a significant giant magnetoimpedance (GMI) effect of up to 320% in a frequency range of 1-100 MHz due to stress enhanced transverse magneto-anisotropy With increasing quantities of embedded wires from 1 to 3 the maximum GMI ratio is enhanced significantly by more than 35% making the resultant composite favourable for field sensing applications The microwire-composite also shows superior stress sensing resolution as high as 134 5 kHz/microstrain which is about 26 times higher than the recently proposed SRR-based sensor As evidenced by the structural examination and tensile tests the extremely small volume fraction of microwires (similar to 0 01 vol %) allows the wire-composites to retain their mechanical integrity and performance (C) 2010 Elsevier Ltd All rights reserved