This blog is based on the recent review “4D Printing of Natural Materials” published in Sustainable Materials and Technologies (2025) by Beatriz Arsuffi and co-authors Tommaso Magrini, Mathilde Champeau, Gilberto Siqueira, and Silvia Titotto. The work, led in part by researchers from Empa – Swiss Federal Laboratories for Materials Science and Technology, explores how natural materials such as wood, cellulose, and lignin can transform 4D printing into a more sustainable and bio-based technology — a vision that closely aligns with the Bio-LUSH project’s mission to advance green material innovation in Europe.
Imagine materials that can move, bend, or transform on their own — acting like soft robots, but without batteries or motors. Instead, they respond naturally to humidity, temperature, or light.
Welcome to the fascinating world of 4D printing — where time becomes the fourth dimension of design.
In essence, 4D printing builds on 3D printing, but adds a new layer — responsiveness. When exposed to external stimuli such as moisture or heat, 4D-printed structures can change their shape or properties over time, creating dynamic materials that adapt to their surroundings.
The Sustainability Shift
Until now, most 4D printing research has relied on synthetic “smart” materials, which often come at a high environmental cost. That’s why researchers like Beatriz Arsuffi and her team are taking a greener route — exploring how natural and bio-based materials such as wood, cellulose, lignin, alginate, and silk can serve as the building blocks for the next generation of smart, sustainable designs.
These materials are renewable, biodegradable, and abundant, making them ideal for reducing waste and carbon emissions. Many even have built-in responsiveness — wood expands and contracts with moisture, while natural fibers like flax subtly move as they absorb water.
Nature as the Engineer
Nature has had millions of years to perfect functional design, and 4D printing borrows this wisdom through bio-inspired engineering — creating responsive structures without electronics. For example, wood-based biocomposites can be programmed to bend or twist when exposed to humidity, mimicking natural movement. Cellulose nanofibers, on the other hand, can direct how a structure folds or swells, offering precise control for applications such as smart packaging or biomedical scaffolds.
Why It Matters for Bio-LUSH
For the Bio-LUSH project, this concept aligns perfectly with our mission to advance bio-based innovation in sustainable materials. 4D printing shows how bio-based fibers and natural polymers can do more than replace synthetics — they can become active, intelligent materials that interact with their environment.
The review highlights how integrating such programmable, living-like behaviors into bio-based composites could revolutionize fields from textiles and packaging to robotics and medicine. Imagine a biodegradable fabric that adjusts its breathability with humidity, or an edible package that changes shape to signal freshness — both powered by nature’s own material intelligence.
Looking Ahead
While the technology is still in its early stages, this work reminds us that sustainability must be built into innovation from the start. As 4D printing continues to evolve, the shift toward renewable and biodegradable smart materials could reshape and re-define the entire material life cycle.
