Stress and Magnetic Field Bimode Detection Sensors Based on Flexible CI/CNTs–PDMS Sponges

This work reports porous carbonyl iron particles/multiwalled carbon nanotubes–polydimethylsiloxane composites (PCMCs) with high flexibility and low density. In comparison to the solid product, the porous PCMC possesses a larger elongation and deformation. Because of the excellent magnetic–mechanic–electric coupling performance, the flexible composite exhibits bimode sensitivity to both the external stresses and magnetic field. Typically, the normalized resistance variation (ΔR/R) of PCMC reaches 82.8% and 52.2% when the compression strain and tension strain are 60% and 50%, respectively. Moreover, the ΔR/R induced by bending, twisting, and magnetostress also changes remarkably. When a 144 mT magnetic field is applied, the ΔR/R of PCMC increases with 3.6%. To further understand the magnetic–mechanic–electric coupling mechanism, a conductive network sensing model is proposed and analyzed. Finally, on the basis of the bimode PCMC sensor array, a smart chessboard which can precisely discriminate special chess...