Hard Disk Drive Voice-Coil Laser Shutter Actuator

Seems like there is no end to the uses of old hard drives. This hack uses the voice coil of a used hard drive to act as a Laser Shutter.
Thanks for the tip Robo.

“We have developed a high-speed laser shutter based on voice-coil actuators found in generic hard disk drives. We have enhanced the shutter with a new driver circuit described below and a notched flag, achieving 500ns rise time and sub-microsecond pulse durations. The shutter is readily constructed from a disassembled hard drive (as shown in an early prototype in the photo above), with the addition of a simple drive circuit. A high-current opamp (e.g. L165V or OPA548) can be used, but requires a bipolar power supply, and generally some sort of pulse shaping. The circuit in our paper, designed by Sandor Szilagyi, provides very fast switching, a small holding current, and bidirectional drive from a unipolar supply.”