Leather gives us that distinctive, cool look, and that’s why a lot of us like it. And if you don’t like real, animal skin leather, the sustainable alternatives around us are plenty nowadays.
But this one’s interesting because it involves 3D printing. We have researchers at Tufts University School of Engineering to thank for that.
They’ve developed an alternative to leather with similar texture and flexibility & stiffness using sustainable, environment-friendly materials.
The material in focus is silk. But the engineers don’t weave it into fabric and instead break down the fibers from silkworm cocoons into their protein components. After that, they repurpose the proteins to form the leather-like material.
Because this silk-based leather has similar physical properties to real leather, it can withstand the folding, piercing, and stretching typically used to create leather goods.
Additionally, we can stitch together pieces of material and attach hardware such as rivets, grommets, handles and clasps. And, we can print the leather into different patterns and textures.
The engineers said, “Our work is centered on the use of naturally-derived materials that minimize the use of toxic chemicals while maintaining material performance so as to provide alternatives for products that are commonly and widely used today.
“By using silk, as well as cellulose from textile and agricultural waste and chitosan from shell-fish waste, and all the relatively gentle chemistries used to combine them, we are making progress towards this goal.”
Silk-based leather vs other leather alternatives
According to Tufts engineers, their leather offers some unique advantages compared to some of the existing leather alternatives.
The manufacturing is water based using only mild chemicals at room temperature, therefore greatly minimizing non-toxic waste.
Since we can 3D print the silk material, we can create regular micropatterns to set the material’s strength and flexibility. And, we can also print macropatterns for aesthetics or non-regular geometrical patterning to mimic the surface texture of real leather.
Thanks to these sustainable materials, this silk-based leather is biodegradable once it enters the waste stream.
Or, if we want, we can redissolve the products and regenerate them into a new, recycled material that we can reprint into new products. Simply put, these are recyclable (although I don’t know how many times we can do that).
This is not the first silk-based stuff that Tufts University has made. The engineers at The Silklab have made implantable medical devices to architectural materials.
First author of the study Laia Mogas-Soldevila said, “That’s the advantage of using silk protein over other methods — it has a well-established, versatile chemistry which we can use to tune the qualities of the material and embed smart elements like sensing molecules,”
“So while there may be many options for leather-like materials, silk-based leather has the potential to be most amenable to innovative designs.”
3D printed, sustainable ivory
If I look at history, only God knows how many elephants were slaughtered in order to get their tusks. We see them in old pianos (or harpsichords?) art objects and many more.
It was only in 1989 that ivory trade was banned internationally in order to protect and preserve their populations.
There have been efforts to substitute ivory. And sometimes we need alternative materials to restore ivory parts of old art objects. But bones, shells, or plastics haven’t delivered satisfactory results so far.
TU Wien (Vienna) and the 3D printing company Cubicure GmbH have developed a high-tech substitute called “Digory”. It consists of synthetic resin and calcium phosphate particles.
Those materials get processed in a hot, liquid state and hardened in the 3D printer with UV rays, exactly in the desired shape. The engineers then cured the material layer by layer using a UV laser until the “raw” product is finished.
Thaddäa Rath explained, “You also have to bear in mind that ivory is translucent. Only if you use the right amount of calcium phosphate will the material have the same translucent properties as ivory.”
When the raw product’s done, they can polish and color match it to create authentic-looking ivory substitute.
The team achieved good results with black tea. Also, they can add the characteristic dark lines that normally run through ivory later on with high precision.
The story behind the stable, true-to-life ivory substitute
Prof. Jürgen Stampfl from the Institute of Materials Science and Technology at TU Wien said, “The research project began with a valuable 17th-century state casket in the parish church of Mauerbach.
“It is decorated with small ivory ornaments, some of which have been lost over time. The question was whether they could be replaced with 3D printing technology.”
The team has made efforts before with similar materials. They’ve also worked with ceramic materials used for dental technology. Still, it wasn’t adequate.
According to the team, it was a challenging task to develop a suitable substitute for ivory.
Rath said, “We had to fulfil a whole range of requirements at the same time. The material should not only look like ivory, the strength and stiffness must also be right, and the material should be machinable.”
Will humans finally spare tusks at last?
For now, the 3D printing technology for ivory alternative only benefits the field of restoration. Nonetheless, this is a big step forward.
According to the team, compared to other alternatives, their new material is more beautiful and easier to work with—overall it’s better.
And thanks to 3D technology, it’s possible to reproduce the finest details automatically. Restoration efforts won’t need to carve them out of ivory substitute material anymore because they can press buttons and wait.
Konstanze Seidler said, “With our specially developed 3D printing systems, we process different material formulations for completely different areas of application, but this project was also something new for us.
“In any case, it is further proof of how diverse the possible applications of stereolithography are.”
So unfortunately, the 3D ivory is only in a rather small scale so far. But we shouldn’t lose hope, because this development is a good stepping stone.
The team hopes that this “Digory” will become generally accepted in the future. Because, their new material is an aesthetic and mechanically high-quality ivory substitute, so that elephants won’t need to lose their tusks anymore.