This Valentine’s Day, show your affection with a gift you make yourself. You could mix up a tasty treat, such as these personalized candy hearts, but pretty much anyone can do that. Instead, choose a love-themed project that demonstrates your science savvy, your DIY chops—or both.

Falling Fast


A Geekier Card

A geeky card is all well and good, but what about one to demonstrate that your love is electric? This DIY card uses conductive ink to power a light-up robot. Cute and affectionate, the love-bot should earn a glowing review. Difficulty: Three out of five hearts

Bath Bombs

If you want to pamper your significant other, a romantic bubble bath should do the trick. Bring it to the next level with these homemade bath bombs. Best of all, the recipe makes about 12 chunks of sweet-scented fizzy goodness—so you can save the leftovers for your own time in the tub. Difficulty: Two out of five hearts

Wear Your Heart (Monitor) On Your Sleeve

For a wearable token of your affection, try this electronics project. By connecting a cardiac monitor to a set of red LEDs, you can create a heart-shaped pattern that flashes brightly with the wearer’s every heart beat. Difficulty: Four out of five hearts

Put A Blinky Ring On It

In 2015, engineer Andrew Martin used LEDs to create a ring that can blink out any date. He got the idea from a fictional engagement ring that flashed the date that the groom and bride met. You don’t need to use a marriage proposal as an excuse to hack together your own blinky ring—it works as a Valentine’s gift, too. Difficulty: Three out of five hearts

Go All-In With A DIY Engagement Ring

Novelty rings are sweet. But if you actually plan to pop the question on Valentine’s Day—and you want to make the ring yourself—you’ll need to consult with a professional. That’s what Popular Science contributing editor Mike Haney did: He forged an engagement ring for his then-girlfriend with help from jewelry maker Sam Abbay. Difficulty: Five out of five hearts