Hardware

Voice Coil Actuator

A voice coil actuator is a direct-drive electromagnetic actuator in which a coil moves within a permanent-magnet field, producing force proportional to current over a short stroke, with no cogging, backlash, or gearing. Its low moving mass and clean force-current relationship give it exceptional bandwidth and force fidelity, which is why it appears in haptic interfaces, fast fine-positioning stages, high-speed grippers, and optical focus mechanisms.

Why it matters for physical AI

High-bandwidth, backdrivable force sources are essential for rendering haptic feedback in teleoperation and for delicate contact tasks, where geared actuators are too stiff and slow to react to force transients.