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Anisotropic Magnetoresistance (AMR) Sensor

Rotate an external field over a thin ferromagnetic strip and watch its electrical resistance follow the AMR law R(theta) = R_perp + (R_par - R_perp) cos^2(theta), the effect behind compasses, wheel-speed sensors and early hard-drive heads.

Physics & Mechanics3DModerate60 FPS📱 Mobile-adapted⇄ 2D version

A thin permalloy strip carries a sense current while an external magnetic field, swept through any angle, drags the strip's own magnetization around with it. Spin-orbit coupling ties the strip's electrical resistance to the angle between that magnetization and the current — R(θ) = R⊥ + (R∥ − R⊥)cos²θ — so rotating the field visibly changes the live resistance, ΔR/R and dissipated power readouts. A relaxation model makes the magnetization lag behind a weak field, reproducing the same nonlinearity that real AMR compasses and wheel-speed sensors are engineered around, and a material switch swaps in permalloy, cobalt or iron to compare how differently each ferromagnet responds.

⚙ Under the hood

Rotate an external magnetic field over a thin ferromagnetic strip and watch its electrical resistance follow the AMR law R(theta) = R_perp + (R_par - R_perp) cos^2(theta), the spin-orbit scattering effect behind electronic compasses, wheel-speed sensors and early hard-drive read heads.

spintronicsmagnetoresistanceAMRsensorsferromagnetismspin-orbit coupling

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install