Remember those hilariously bizarre Japanese cat ears you could manipulate with your mind? If you have a 3D printer, a Mindwave headset, some technical know-how, and a little bit of elbow grease, you can build your own pair.
https://gizmodo.com/cybernetic-cat-ears-read-your-brainwaves-and-let-the-wo-5799013
Over at Thingiverse, Joshua DiMauro has posted a guide on how to build these ears. The project isn’t exactly for beginners, as Josh concedes — “Let’s be honest, this is a lot of work to go to in order to make some kitty ears [and] I’m releasing it here because I’m curious what else people could make based on it.”