Space & Innovation

4-D Printer Creates Shapeshifting Orchid

The technique could be used to develop new kinds of smart clothing that both repels water and breathes, or flexible scaffolding for printed organs.

Printing in three dimensions is so 2015. How about adding a fourth dimension - time?

That's what researchers at Harvard University have done in creating a unique polymer-based flower structure that soaks up water like a sponge and changes its shape just like a real orchid.

Open Wide: 3D-Printed Foods Made To Eat: Photos

While the folding fake flower is, at the moment, a cool lab experiment, the concepts explored in the study could be used to develop new kinds of smart clothing that can repel water and breathe at the same time, or perhaps a new kind of flexible scaffolding for a printed human organ.

"We were inspired by the complex shape changes that you see that plants display," said Jennifer Lewis, professor at Harvard University's Wyss Institute for Biologically Inspired Engineering, and an author on the report published this week in Nature Materials. "As we began to look into the origin of the shape change, we realize it was a simple process."

Lewis and her colleagues have already created 3-D self-folding origami structures. They have also assembled 3-D tissue with blood vessels. But this project adds another level of complexity, even if the inspiration seemed easy.

The ink in this printer is a jello-like substance that contains tiny fibers of cellulose derived from wood. | Harvard University/Wyss Institute for Biologically Inspired Engineering

The Harvard team came up with hydrogel composites -- think jello -- that contain cellulose fibrils derived from wood and are similar to the tiny structures that allow plants to change their shape.

"They respond to water. As they hydrate, they begin to swell," Lewis said. The 3-D printer was programmed to give some parts of the structure more stiffness, and other parts flexibility. The difference in flexibility makes the entire flower curl up like a real one when dropped in water.

4-D Printer Makes Shape-Shifting Wood

"We can locally encode changes in swelling behavior which give rise to a lot of complexity to have bending, rustling and twisting," said Lewis, who conducted the research along with co-lead authors A. Sydney Gladman, a graduate research assistant and Elisabetta Matsumoto, a postdoctoral fellow, both at Wyss.

The secret to the folding orchid is the design of the special ink that contains the hydrogels. The composite ink that the team uses flows like liquid through the printer head, yet solidifies once printed.

"We can swap one hydrogel for another, or swap cellulose fibrils for carbon nanotubes or metal nanorods," Lewis explained. "It opens the ability to create scaffolds for tissue engineering or for tissue repair." The video below shows how it work.

The scientists are also considering the idea of printing these flexible structures onto a textile or cloth and having it spontaneously change shape. "We could use the concept to go from a flat fabric to something that might resemble the upper of a shoe," Lewis said. The biggest hurdles remain the durability and washability of such a textile.

Lewis, who already holds eight patents on various 3-D printing projects, says this experiment is just the beginning.

Skylar Tibbit, research scientist in the school of architecture at the Massachusetts Institute of Technology and a pioneer in 4-D printing techniques, says the main contribution of Lewis' group is the control of materials in producing the polymer flower.

"They have much more control and alignment," Tibbit said. "Their modeling tools are much more advanced. Their results are fairly complex, and there are lots of movements in different directions."

Tibbit says there are several research groups around the world who are pursuing various 4-D printing techniques to develop both medical devices and new kinds of micro-electronics.

Ink seems so retro now that machines can custom-print myriad 3-D objects, including snacks. Here are some of the most impressive edibles to emerge from 3-D printers so far.

Cornell University’s Creative Machines Lab

is at the forefront of 3-D printed food. The lab’s Fab@Home project led by PhD candidate Jeffrey Ian Lipton uses solid freeform fabrication to print interesting snacks. Lab researchers worked with the French Culinary Institute to print this space shuttle from cheese.

3-D Printing Is Getting Ready to Explode

Printing with chocolate is a no-brainer given its consistency but what used to be a novelty has started going mainstream. Chocolate companies are using 3-D printing tech in new ways, like this

tractor

printed for Nestlé and Android KitKat’s

Chocnology

exhibition.

Using food like ink can be much trickier than generating a mold from 3-D tech. Several years ago

Windell Oskay

and his team at

Evil Mad Scientist Laboratories

custom-built a 3-D fabricator that fused sugar together into sculptures. More recently 3D Systems released the ChefJet printer to produce confections and cake-toppers.

One day the pizza question could be, Fresh, frozen or printed? The Barcelona-based startup Natural Machines printed fresh pizzas using a 3-D machine prototype called Foodini in 2013. At the same time, NASA gave a grant to the Systems and Materials Research Corporation in Austin to develop pizza-printing capabilities for space.

3D-Printed Pizza to Feed Colonists on Mars

The crew at Cornell University’s Creative Machines Lab did print thick cookies containing the letter C but German designer

Ralf Holleis

produced fewer crumbs. He collaborated with a professor at the University of Applied Sciences Coburg to print

holiday cookies

from red and green colored dough.

Printed meat doesn’t sound all that appetizing but that hasn’t stopped anyone from trying. The startup

Modern Meadow

is working on developing humane, bioprinted meat while

Natural Machines

used their Foodini to create real swirled hamburgers -- as well as the buns and cheese to go on top.

These chips might look like ramen noodles but researchers at the Cornell Creative Machines Lab printed them from corn dough. The flower shape allowed for even frying, Fast Company reported. If you want pasta, Natural Machines says its Foodini printer can serve up gnocchi and ravioli.

The Dutch consultancy T

NO Research

envisions using 3-D printing to address world hunger, although some might squirm at their proposals. Their food printer can generate nutrient-rich snacks from alternative ingredients like algae and even mealworms.

If telling kids to eat broccoli because it’s “little trees” doesn’t work, perhaps Natural Machines’ 3-D printed

spinach quiche

will. To tempt picky young eaters, the Spanish startup produced vegetable snacks in the shape of butterflies and dinosaurs using their Foodini printer.