If you're like my roommate and buy groceries only to lose track of when they're going to go bad, this new research from MIT might interest you -- it's a wireless food spoilage sensor that detects when food is about to go bad and sends an alert to your smartphone so you can do the needful.
This inexpensive sensor identifies spoiled food early be detecting gases in the air, before sharing its data with your smartphone. The sensors are actually modified near-field communication (NFC) tags, which are often used as proximity sensors. The researchers punched a whole in NFC tags' electronic circuits and replaced the missing links with carbon nanotubes designed to detect gases.
While these sensors can be used to detect rotting food, they could potentially be used to detect everything from pollutants to explosives.