Flowers and candy are fine, but if quadratic equations or astrophysics are what really make your sweetheart's heart go pitter-patter, you may need something different to show your love this Valentine's Day. Looking for something other than conversation heart cut-outs? Here are some great DIY Valentine card ideas for you and all of the STEM nerds in your life. (That's science, technology, engineering and math in case you're wondering.)

You're Electric Valentines

1. You're Electric Valentines from Left Brain Craft Brain. Electrical circuit paint, LED batteries, and a design simple enough that even a child (or artistically challenged adult) can master. Oh, and the directions are a breeze to understand. Need I say more?

Chemical CuTe

2. Chemical CuTe. This simple Valentine design was uploaded on Pinterest by user Laurin Nicole. Perfect for the periodic table lover in your life.

All The Love In The World Valentines

3. All The Love In The World Valentines. These DIY Valentines from Fabulessly Frugal are a great option for those who want to give a toy instead of candy. They can also be customized to match the planetary preferences of your Valentine.

Valentine's Day Marble Maze

4. Valentine's Day Marble Maze by The Inspired Treehouse. It's a card! It's a toy! It's a fun and easy Valentine's challenge! And really, it couldn't be any simpler to make.

I've got my eye on you valentine

5. 'I've Got My Eye On You' Valentines by Dandee Designs. Reasons why I LOVE this card design:

A. It's science-y.

B. It's ridiculously easy to make.

C. You give a kid (or an adult) a magnifying glass and suddenly they start looking at the world they live in more closely — and that's good stuff.

Fun with Dopamine card

6. Fun with Dopamine. This Valentine card design was uploaded by Pinterest user Tara McGeehan. And it's perfect for the brain hormone researcher or neuroscientist in your life.

Valentine Operation card

7. Valentine Operation card uploaded by mathiemom on Instructables. As mathiemom describes it, this card is "a game, a gift, and a lesson in eclectic circuits." What says 'I love you' more than that?

Looking for even easier valentine ideas for STEM nerds? Check out these awesome printable chemistry Valentine's, sure to make your loved one's heart phosphoresce.