Imagine this scenario: You ordered an ornate oak desk online, and when it arrives a few days later, you open the package breathlessly. The box is lighter than expected, containing only a flat piece of wet-inked wood that resembles maple candy. But after the ink dries, the wood miraculously transforms into the item you ordered online, avoiding the need for frustrating hours-long assembly sessions.
Such a product is not possible. Even. But it is the goal of Doron Kam, a doctoral student in materials science at the Hebrew University of Jerusalem in Israel, who recently presented his work with colleagues at the fall meeting of the American Chemical Society. Kam’s proposed printing technique creates wooden objects that don’t require us to saw, carve, or bend, and can transform on their own thanks to what seems like magic, but actually required meticulous planning and a high-tech 3D printer.
The futuristic concept takes advantage of warping, a natural phenomenon in wood that is often feared by designers and homeowners alike. Wood wets and dries unevenly, creating some wacky shapes, and no one wants a floor that creaks and sags or a dresser with weird curves. But Kam and his colleagues use this phenomenon to his advantage.
What’s new – Kam and his fellow researchers found a way to print flat sheets of wood that form 3D shapes when prompted with a certain stimulus, such as a change in pH, temperature, or humidity. They were inspired by the natural curves of warped wood. It may look interesting in a forest, but warping can ruin human-built items like furniture, flooring, or even wooden structures like a gazebo or cabin.
Kam’s proposed printing technique creates wooden objects that do not require us to saw, carve or bend them, and can transform themselves thanks to what seems like magic.
Unlike what happens in nature (or in a flooded house), the researchers found a way to dictate how a piece of wood will turn out when wet. They achieved this by adjusting various factors in the printing process, including print speed and precise ink placement. Eventually, this manufacturing process could create custom furniture that is easy to ship and requires no effort from the customer (other than opening the box).
But the project is intended for more than just tables and chairs, explains Kam. “If we invest enough time and resources, [this method] it can produce really interesting and valuable products,” he says. “The way we’re showing it is just working the wood.”
The broader goal of Kam’s research: To create the objects of the future, we must completely rethink design.
Here is the background – Kam’s team is not the first to propose materials that deform over time. He is part of a growing community of researchers working on 4D printing, whose goal is to take its 3D predecessor a step further by manipulating how objects will change after they are printed.
This idea challenges the way we have approached design for centuries, says Kam. Until recently, he explains, the goal was to create structures that would remain the same over time to ensure their durability. “What we’re proposing is a little bit different… a more responsive material,” says Kam. “The concept of engineering is changing.”
These evolving materials reflect the dynamic nature of our environment, says Tiffany Cheng, a doctoral student researching bioinspired 4D printing at the University of Stuttgart in Germany.
“In nature, things are always changing, always adapting,” she says. “There is never really just one state of being.”
But the current tools used for 3D printing limit our creativity, Cheng and Kam say, since they are designed to generate static objects.
Like the Hebrew University of Jerusalem team, Cheng is looking for print materials that can transform when presented with certain stimuli, such as increased humidity or temperature. She says it was “mind blowing” to learn about responsive design, which opens up countless possibilities for a single article.
Why does it matter? At this time, the Kam team has only made small prototypes and is still thinking about how to successfully scale them. After materials scientists like him learn the basics, he says, it’s up to designers to put them to work.
So if they work, responsive materials could revolutionize a variety of fields. For example, imagine a cast for a broken arm that sits in the proper position, says Cheng, instead of having to visit your doctor every month to have it adjusted. In addition to medical applications, he is currently working on a building facade that can adjust its shade based on factors such as outside temperature.
Forward-thinking 4D printing research also prioritizes sustainability. Currently, multidimensional printing relies on synthetic materials, including gels and elastomers, which produce mountains of waste.
But green ingredients can change that: A few years ago, the Hebrew University team created a water-based ink made from microparticles of wood waste called “wood flour,” which are mixed with binding substances from plants (including nanocrystals). made of cellulose). , or the main component of the cell walls of a plant). This concoction can even be created from leftover wood, avoiding the need to cut down trees.
Kam sees a future where “you can make your own product and after a few years you can rebuild it over and over again,” he says.
What did you do – The researchers found that they can position the wood stain in certain directions to dictate how it will transform when the material dries. For example, a series of lines emanating from a central point can dry into a cone-like structure. Stacking also helps achieve greater accuracy: stacking two rectangular layers that have been printed in different orientations can create a helix shape after the ink dries.
They can also adjust the print speed to dictate the final shape of the object. The material shrinks in a direction that is perpendicular to the wood fibers in the ink, and the specific print speed changes the alignment of the wood fibers. Ultimately, a slower print ensures a more random alignment of the particles and causes shrinkage in all directions, while a faster print aligns the fibers and can control shrinkage in a specific direction.
Whats Next – In the future, Kam and his fellow researchers plan to combine specific shapes, such as mounts, domes, and propellers, to produce more complex final objects. Currently, it is difficult for the wood to dry without cracking due to its brittle texture, so it must be placed on a sheet when airing. They are also considering how to make the shrinkage reversible.
Both Cheng and Kam also hope to create software that anyone can use to design and print their items of choice, such as a medical technician looking to create a custom splint, or even an owner with a specific type of desk in mind.
But several obstacles remain. For one thing, multidimensional printing is currently extremely slow: it can take hours or days to manufacture a single part. However, some applications are likely to demand a faster timeline, particularly in the medical field. And today’s print materials are pretty limited: You can be pretty creative when manipulating an item on the printer, Cheng says, but a given material can’t do much.
In the future, it is up to experts like Cheng and Kam to test these limits. The sooner they can pull it off, the sooner we can say goodbye to Ikea’s indecipherable instructions.