Deep in the halls of the engineering school at Columbia University, behind a locked set of blue doors, is one of the coolest labs I've ever seen.

Oh my gosh, there's so many toys in here.

This is the Creative Machines Lab, where we look at all types of robots.

Hod Lipson runs this lab. He's a roboticist and professor of engineering and data science.

The shelves and tabletops are packed with his students' creations.

Blue robot heads, a robot that looks like a spider with spiky legs.

It kind of looks like a prop shop, like on a Hollywood set or something.

Like I could see all these things being in some kind of sci-fi movie.

But I'm here to look at a very different kind of toy.

A 3D printer that prepares and cooks food.

It started for us as a really as a frivolous activity.

About 20 years ago, when 3D printing was taking off,

HOD students started playing around with ingredients like frosting and easy cheese,

late-night snacks the grad students had on hand.

And that opened a door.

My students started playing around with sort of biological materials.

That kind of branched off into two areas.

One is an area called bioprinting, which is now actually a big field,

printing organs, printing biological models to test medicine.

I heard someone printed an ear.

That's right.

So one of my former students about two years ago printed an ear that was actually made from cells

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