"So, this is about a lot more than cigarette butts, and the researchers suggest a variety of other potential use cases, including spraying weeds in crop fields,

"So, this is about a lot more than cigarette butts, and the researchers suggest a variety of other potential use cases, including spraying weeds in crop fields, inspecting cracks in infrastructure, and placing nails and rivets during construction." How do the sifting machines differentiate between cigarette butts and little sticks/rocks/pieces of driftwood &c? If this dog vacuum thing is not too noisy and can unobtrusively navigate an area it seems like it might be a pleasant "always on" addition. I used to work a maintenance job where I'd show up at 1am and sweep up dozens of cigarette butts from the parking lot. Then I'd pop back out around dawn and there'd be a dozen new ones! It really is a constant and ongoing issue. Perhaps the robot could monitor the area for active smokers and just go over and offer up an ash tray.