Some people love capsaicin, the compound in chili peppers that gives them their heat. Others avoid it whenever possible. Regardless, it can be hard to tell how hot something is before tasting it, which is why researchers have created this Capsaicin Detector. Shaped like a chili pepper — because why not — it uses a paper-based electrochemical sensor to accurately detect the presence of capsaicin and then displays the results on an attached smartphone. It's unlikely to hit the market any time soon, although there's surely a market for it if/when it does.
Photos: Adapted from ACS Applied Nano Materials 2020