Terfenol-D Magnetostrictive Actuator

Terfenol-D is the archetypal giant-magnetostriction alloy: apply an axial magnetic field and its internal magnetic domains rotate, stretching the rod by up to a few hundred parts per thousand of a percent — enough to drive sonar transducers, fuel injectors, and precision industrial actuators without a single moving part besides the lattice itself. This simulator renders a Terfenol-D rod inside its drive solenoid, animates the domain-rotation mechanism behind the strain, and lets you sweep a bias field and AC drive field to see why real actuators are always operated pre-biased on the steep part of the strain-vs-field curve rather than driven from zero field.