I have been highly interested in inventing conductive interfaces for quite some time. I have quite a few companies these days interested in having me develop unique ways to control machines / robots.
Maybe it's gesture based to control drones or flying robots.
Other opportunities involve gesturing on flat surfaces to activate light and/or sound:
I believe that there many opportunities within unique formulations of ink.
In the past, I have invented several kinds of systems to interpret touch, hovering, gesturing and the like.
Above is a video I made while developing a printed, conductive ink interface.