Fig. 1: Fabrication and self-healing of magnetoresistive sensors aided by AMF.

a Schematic illustration of fabrication process for magnetoresistive sensors. b Electrical resistance of magnetoresistive composite during curing. c, d Photographs and schematics of the magnetoresistive composite (left to right: original, cutting, healing by 20-s long AMF exposure). Magnetized Ni₈₁Fe₁₉ microparticles lead to an active healing of percolation networks without the need for manual assembly. In (c), the magnetoresistive composite was damaged with micrometer-scaled cracks. In (d), the composite was disconnected with millimeter-scaled gaps and healed in water. Please see Supplementary Movies 1, 3 for details. Scale bars: 400 μm in (c) and 10 mm in (d). e Resistance variation during four cutting/self-healing cycles. The actual time for self-healing was shorter than that displayed, considering a major fraction of no-conductivity time required to generate damage and place into the AMF setup, as observed in Supplementary Movie 2. f Magnetoresistance before and after cutting/healing. The magnetoresistance was characterized by measuring the variation of electrical resistance in a tunable magnetic field, normalized to the original resistance at 0 mT, that is, (R−R₀)/R₀.