It's hard to imagine cardboard being in need of a reinvention. After all, this sturdy old friend has served us well ever since it debuted in China more than 2,000 years ago as sheets of treated mulberry tree bark.

As times changed, we grew to lean on cardboard even more. Everything from take-out food to milk cartons to the mountains of merchandise moved by Amazon every day, rely on these extra-thick sheets of paper.

In recent years, the most dramatic change cardboard has been in its materials, as it incorporated increasing amounts of recycled paper — and that's a good thing, considering how much of it we use.

Even so, cardboard has always been content to be overlooked as we tear into our Christmas presents. Always a bridesmaid...

But today, this humble material stands on the precipice of being interesting.

Engineers at University of Pennsylvania may have taken it to the next level, inventing what they call "nanocardboard" as a replacement for the corrugated variety typically used for shipping.

According to the recently published study, the new material has all the charms of corrugated cardboard — thin, light and yet still sturdy — but adds the prefix "ultra" to all of those qualities.

Researchers say a single square centimeter of the stuff weighs less than a thousandth of a gram. And it leaps back into its original form after being bent in half.

In other words, it outcardboards cardboard. The new material, and the way it's engineered, could be used in countless applications here on Earth. And maybe even beyond.

Nanocardboard as seen under a microscope Nanocardboard derives much of its strength and flexibility from a unique basket weave pattern. (Photo: University of Pennsylvania)

"Corrugated cardboard is generally the sandwich structure people are most familiar with," Igor Bargatin, one of the study authors, notes in a press release on Phys.org.

"It's ubiquitous in shipping because it's both lightweight and stiff," he explains. "But these structures are everywhere; the door to your house is probably a sandwich structure, with solid veneers on either side and a lighter core, such as honeycomb lattice, on the interior."

Indeed, nature itself recognizes the inherent sturdiness of the sandwich structure that corrugated cardboard is modeled after.

"Not surprisingly, evolution has also produced natural sandwich structures in some plant leaves and animal bones, as well as in the microscopic algae called diatoms," explains study co-author Samuel Nicaise in the release

Was anyone actually clambering for a thinner, lighter kind of cardboard? After all, take-out food and Amazon deliveries seem to be getting along just fine sheathed in the classic stuff.

Why skim off even more weight from an already-svelte material?

In a word, space. Literally.

When it comes to building objects for space, lightness, strength and flexibility are critical. Nanocardboard, thanks to that sandwich structure, is also being touted as an excellent thermal insulator — another key consideration for space exploration.

Also, under the intense conditions of space, a material that bends without breaking could be a boon.

"If you apply enough force, you can bend corrugated cardboard sharply, but it will snap; you'll create a crease where it becomes permanently weakened," Bargatin notes. "That's the surprising thing about our nanocardboard; when you bend it, it recovers as if nothing happened. That has no precedent at the macroscale."

At the very least, when we finally pack up the family and move to Mars, Amazon should have no trouble getting those replacement coffee filters to us.

There's a new cardboard in town, and it's super-strong and ultra-flexible
Penn engineers create "nanocardboard," which promises to be sturdier, lighter and thinner than corrugated cardboard.