[russdill]

Bonus points for a USB stick that with the correct knock algorithm (plug in 3 times, unplug for 10 seconds, plug in again) presents a secret partition, otherwise presents a dummy partition.

[microtherion]

With an USB C stick, you could have a knock algorithm that involves plugging it in with a particular orientation pattern as well.

[bArray]

Technically speaking, you could probably also develop a USB-A that could do the same thing with a little mechanical and electric configuration.