Teardown Update: You asked and we answered—here's a closer (and less shakey) shot of that vibrating motor.

We weren't too impressed with the vibrators plain-shiny-metal-box exterior, so we took a rotary tool to the casing in the name of science.

Disclaimer: We were armed with X-Ray images to guide our journey and stumbled upon exactly what we expected: a itty weight between bitty springs.

Linear oscillator is the technical term for a weighted magnetic core shaking between two springy metals. The rate and travel of that vibration simulate tactile feedback, which translates into a virtual click without any external moving parts.