UC San Diego's new sticker turns any cup into a vitamin C tracker
UC San Diego engineers have designed a tiny, battery-free sticker that sticks to your cup and tracks your vitamin C levels in real time—using just sweat from your fingertips.
It's a simple, affordable swap for traditional blood tests, making health tracking way less intimidating.
How it works (and why it's cool)
The Smart Cup sticker collects sweat through a soft hydrogel pad and uses a biofuel cell to power itself—no batteries needed.
After you drink orange juice or take supplements, the sensor checks your vitamin C levels and sends the results wirelessly to a nearby computer via Bluetooth.
Each disposable sticker powered itself for more than two hours using only sweat-derived energy during tests.
Why this could change the game
At only a few cents per sticker (compared to $50 for a blood test), this tech makes regular vitamin C checks much more accessible—especially in places with limited resources.
Plus, it's subtle and easy: just stick it on any cup, no bulky wearables required.