For our first Ideation & Prototyping class, we split into groups to brainstorm a “fantasy device” — something that doesn’t exist, but that we wish existed. My groupmate suggested a device that can open doors without your need to touch them. I’ve seen some tools, especially nowadays, that can open cylindrical doorknobs with a simple hook, so the exercise became more about imagining a device that could open any door — whether its knob is cylindrical, or round, or whether it has a knob at all.
Our rough sketch looked like this:
While holding the round handle, the user can hook the tool around a cylindrical doorknob to pull it; fit the gap around a round knob to twist it; or press on a door without a knob to push it open. Lastly, a keychain loop would be a quick and easy way to keep it safe for when you need it the most.