This 3-D Printed Cap Tells You When Your Milk Has Gone Bad So you don't have to sniff.

By Laura Entis

Opinions expressed by Entrepreneur contributors are their own.

Engineers from UC Berkeley and Taiwan's National Chiao Tung University have created a smart, 3-D printed cap that can determine when food -- in this particular case, milk -- has gone bad. The results were published yesterday in the journal Microsystems & Nanoengineering.

The end result of the study sounds minor, but sniffing out spoiled milk can be tricky. (It always smells a little off to me, while a friend can't seem to register milk's sour notes and is routinely ruining perfectly good bowls of cereal, mac and cheese, mugs of tea, etc. Not the world's most pressing problem, but a problem nonetheless.)

Related: How This Produce Pioneer Popularized the Kiwi and Forever Changed the American Palate

Luckily, the engineers are on it. Using a technology that embeds electrical components into 3-D printed plastics, they've printed a milk cap that contains a resonant circuit able to detect changes in electrical signals caused by the proliferation of bacteria.

To check whether milk has gone bad or not, all you need to do is tip the container over so it comes in contact with the cap. Voila! No sniffing required.

The underlying technology behind the smart milk cap can be used in other food packaging, the researchers believe. "You could imagine a scenario where you can use your cellphone to check the freshness of food while it's still on the store shelves," senior author Liwei Lin said in a statement.

Related: How 3-D Printing Is Sweetening Your Eating Experience (VIDEO)

Laura Entis is a reporter for Fortune.com's Venture section.

Want to be an Entrepreneur Leadership Network contributor? Apply now to join.

Starting a Business

"Nothing Is Obvious the First Time": How This Serial Entrepreneur Is Redefining Sports Media with On3

On3 founder and serial entrepreneur Shannon Terry shares his thoughts on the evolving sports media landscape and his insights on building and growing a business from personal experience.

Business Ideas

70 Small Business Ideas to Start in 2025

We put together a list of the best, most profitable small business ideas for entrepreneurs to pursue in 2025.

Business News

Walmart Is Laying Off Hundreds, Relocating Others as the Company Closes a U.S. Office

Walmart is giving some employees at least a month to decide if they want to relocate.

Growing a Business

What Our Digital World Is Missing — and How I Turned It Into $100 Million After Dropping Out of High School

I went from high school dropout to $100 million CEO by sticking to one very important learning principle.

Growing a Business

This Charleston Hotspot Found an Inflation Loophole That Helps It Avoid Rising Food Costs – Here's Its Secret

Miller's All Day partners with local farmers to combat rising inflation costs and thrive in Charleston's competitive restaurant scene.