Tires made from lettuce

Ainissa Ramirez is a scientist, author, and self-proclaimed science evangelist. She’s the creator of a podcast series called Science Underground. She joins Hari Sreenivasan to discuss how rubber can be made from an unlikely source.


Ainissa Ramirez is a scientist, author, and self-proclaimed science Evangelist.

She's the creator of a podcast series called 'Science Underground.'

She joins me now to discuss how rubber can be made from an unlikely source.

The source is sitting on the table.

It looks like --

Very sad.

It is very sad.

It looks like it shouldn't be eaten but, really, should be turned into tires.

But how do we turn lettuce into tires?

Well, scientists are working on that, converting this sad salad into tires.

It ends up that a tire is made out of rubber.

There's two sources -- natural rubber, which actually comes from Malaysia, Indonesia, and Thailand, and then synthetic rubber, which is a by-product of oil manufacturing.

Neither one are really sustainable.

One travels long distances.

Another one is coming from oil, which is wreaking havoc on the environment.

So, it ends up that plants actually generate natural rubber, and lettuce is actually one of the best at them.

They generate natural rubber.

Generates natural rubber.

How? In their --

Natural rubber is a molecule that kind of looks like a spring.

It looks like a -- It's very elastic.


And the longer it is, the more elastic, the better the quality.

And it ends up that lettuce knows how to do that.

And, so, what scientists are trying to do is -- they're trying to cultivate lettuce to make more of this natural rubber.

And, ultimately, they'd like to figure out how it does that, identify the molecules, identify the process, and then replicate that in the laboratory so that they can make lots of natural rubber.

So, is there a process that would turn this in-- I mean, do we add something to the lettuce to dissolve it and get the rubber in this out of it?

I'm trying to --

No, no.

I know what you're saying.

No, inside the lettuce, it has enzymes and proteins that are fitted in a certain way, and, from that, it can generate natural rubber.

So, there's only a small amount of natural rubber, and what they want to do is be able to increase the amount.

So that's what scientists are looking for.

So, no, you don't have to add anything to it.

All you need is sunshine and water to let lettuce do its thing.

And then what they want to do is enhance lettuce's ability to create this natural rubber.

You know, this is gonna be the reason that lots of 7-year-old boys and possibly girls say, 'Yeah, you know, I'm just going to try to make rubber, mom.

I'd rather not have this part of the meal.'

What are the implications, though, of this kind of a process, if it was to work?

Well, the thing is that rub-- Excuse me.

The thing about lettuce is that it can grow in cold climates, so it can grow in North America.

So we don't have to have it travel from parts of Asia to come to us.

That's the first thing.

It also grows very quickly.

So you can get 2 to 3 harvests of lettuce in a year.

So that's the other implication.

So that's what's positive about that.

And lettuce is not the only plant that does it.

There's actually 2,000 other plants that generate natural rubber.

It's just that it's the best.

And people have already started companies based on using plant technology to create natural rubber.

Wow. I had no idea 2,000 other plants had this.

So, if there are -- I mean, it becomes more sustainable.

That's right.

We don't necessarily have to rely on the by-products from the fossil fuels.


And we don't have to have it coming across Asia, again, using more fossil fuels to get here.

Right. Exactly. Exactly.

And it's an idea that's actually really old.

Thomas Edison had this idea.

He found a plant, a wild flower, called Canadian goldenrod, which creates natural rubber.

And he wanted to do that.

He worked with Henry Ford, because the cars had just started, and they wanted to find another source for natural rubber.

But in the 1930s, they discovered oil and they discovered how to make rubber synthetically.

So what we're doing now is -- we're going back to what Thomas Edison started.

And, so, he had -- Had he actually made -- Had Thomas Edison taken the goldenrod flowers and turned it into a rubber?

That's right. That's right.


But then they stopped, because you can make so much more with synthetic.

And, plus, oil was exciting, organic chemistry was exciting, so there was this huge rush to make things from -- You know, make things massively from this by-product.

Is there any difference in the kind of rubber that would come out, whether it's from synthetic, from a lettuce or from a flower, versus the stuff that we see today?

There's a slight difference.

I don't know it fully, but there is some difference.

But, overall, natural rubber and synthetic rubber operate about the same.

Okay. And rubber bands wouldn't be any less flimsy or --

No, no, no, no.


No, no.

That wouldn't be an issue, yeah.

And, actually, rubber is used in so many different places.

As you said, rubber bands, balloons, boats.

It's every-- Gloves.

There's so many different products.

It's not just tires that this sad bowl of lettuce would affect.

[ Laughing ] All right.

Ainissa Ramirez, thanks so much for joining us.

Thank you.