Arduino-Controlled Lock from nootropicdesign on Vimeo.
This kit uses a CD-ROM drive and an Arduino board to build a clever robotic lock. This dude used a bolt to create the project and it’s voice activated.
I’d be a little worried that anyone could come up to the device and say “Unlock,” but what do I know about robotics. Also, that bolt looks flimsy. Maybe he could make a new system that shoots spikes through the floor?