A trailblazing 3D printing technique now allows precise control over color, shade, and texture, all with just a single material.This new approach, known as speed-modulated ironing, not only speeds up the production process but also significantly reduces waste.Developed by researchers at the Massachusetts Institute of Technology (MIT) in Cambridge and Delft University of Technology (TU Delft) in the Netherlands, this technique marks a major leap forward in 3D printing technology.Specifically, it promises a faster and more sustainable solution than traditional approaches relying on multiple materials and nozzle changes.
The details of this innovation have been documented in a paper titled Speed-Modulated Ironing: High-Resolution Shade and Texture Gradients in Single-Material 3D Printing, published in the Association for Computing Machinery (ACM) Digital Library.Speed-modulated ironing enables makers to fabricate objects with varied colors and textures, like these owls, using only one material with high precision.Image courtesy of the researchers at MIT and TU Delft.Multimaterial 3D printing has long been known for its ability to create objects with multiple colors and textures.While these methods are effective, they often rely on more complicated setups, like multi-material extrusion, which can be less efficient and generate waste.
For example, some techniques combine multiple filaments or nozzles to achieve similar results but tend to be slower and create more waste during production.The MIT-led team’s new method addresses these problems.The real breakthrough here is using heat-responsive filaments and a dual-nozzle system.In the first step, the printer deposits a base material, after which the second nozzle, resembling an iron, moves over the printed layer to adjust the material’s properties.
Instead of switching between different materials or nozzles, the printer activates changes in the object’s appearance—such as color shifts, translucency, or surface roughness—by varying the speed at which the second nozzle passes over the material.According to the researchers, this speed modulation allows the material to heat to different degrees, triggering specific changes.TU Delft’s lead researcher Mehmet Özdemir says, “In attempting to utilize the temperature response, we realized that varying the speed of a nozzle is much more accurate and instant compared to changing its temperature.This is the key for our fine-grained control of the applied heat.”The team mainly used Ultimaker printers (models 3, S3, S5, and S7) to test how different filaments responded to their speed-modulated ironing method.
They adjusted the printing instructions (G-code) for Ultimaker’s Cura software to control layer heights and the ironing process.While they used Ultimaker printers, the researchers say that their method can work with other FDM 3D printers.In future work, they plan to integrate the technique into existing slicer software to improve print speed, resolution, and overall efficiency without additional hardware modifications.A major advantage of this approach is that the second nozzle only applies heat, and its temperature remains constant.
By controlling how fast the nozzle moves, researchers can control how much heat is transferred to the material.This creates fine-tuned shades, colors, and textures without additional materials or complex hardware.“It is similar to what happens if you move your finger over a flame.If you move it quickly, you might not be burned, but if you drag it across the flame slowly, your finger will reach a higher temperature,” explains Marwa AlAlawi, a mechanical engineering graduate student at MIT and one of the researchers involved in the project.The process of the Speed-Modulated Ironing.
Image courtesy of the researchers at MIT and TU Delft.With this new technique, designers can create highly personalized objects faster and with fewer resources.For example, the team demonstrated their method by producing translucent water bottles with different opacity.The printer could generate opaque sections by ironing the material at low speeds, while higher speeds created translucent areas.
They also produced textured bicycle handles, which could help users with weak grips hold on more comfortably.This level of customization is typically more complex and less efficient than conventional 3D printing techniques, which often involve additional steps and resources.“Today, we have desktop printers that use a smart combination of a few inks to generate a range of shades and textures.We want to be able to do the same thing with a 3D printer—use a limited set of materials to create a much more diverse set of characteristics for 3D printed objects,” says Mustafa Doğa Doğan, co-author of the research paper on speed-modulated ironing.Doğan worked on this innovative technique while at MIT, where he completed his doctoral degree in 2024.
He is now a research scientist at Adobe in Basel, Switzerland, and recently shared his excitement on social media as the project is currently being presented at this year’s ACM Symposium on User Interface Software and Technology (UIST) in Pennsylvania.Speed-modulated ironing is a novel 3D printing technique for FDM 3D printers to program visual and tactile properties at a high resolution.Image courtesy of the researchers at MIT and TU Delft.One of the most compelling features of this technique is its efficiency.In traditional multimaterial 3D printing, each material switches not only requires the printer to discard leftover material but also results in downtime as the printer recalibrates for the next material.
This process adds hours to the printing job and wastes material.Instead, the researchers explain that speed-modulated ironing significantly reduces these inefficiencies.The team behind the project tested the method using three types of heat-responsive filaments.One was a foaming polymer, which could change opacity, shade, and texture depending on how much heat was applied.
The other two materials, filled with wood and cork fibers, respectively, could be “charred” at varying intensity levels to create darker shades.To ensure the accuracy of this method, the researchers developed a model that predicts how much heat the second nozzle will transfer to the material at different speeds.This model is the foundation for a user interface that automatically generates printing instructions to achieve specific colors, textures, or shades.Examples showing local shade variations, each object was printed using a single material; either Corkfill or Woodfill.Image courtesy of the researchers at MIT and TU Delft.“There are a lot of inputs that can affect the results we get.
We are modeling something that is very complicated, but we also want to make sure the results are fine-grained,” says AlAlawi.The team considered different variables, such as the heat dissipation from fans, room temperature, and the properties of the specific filaments they were working with.They incorporated all of these factors into a user-friendly interface that simplifies the process for designers, allowing them to focus on the final appearance of their product without manually adjusting settings during the print.Liquid containers printed using “natural color” LW-PLA.Regions ironed at a low speed become opaque, while regions ironed at a high speed remain translucent.
Image courtesy of the researchers at MIT and TU Delft.While the speed-modulated ironing technique is still in its early stages, the researchers believe it has the potential to reimagine 3D printing.By making the process faster, more precise, and less wasteful, it could pave the way for more sustainable manufacturing in industries ranging from consumer products to healthcare.The team is already exploring the possibility of using this method with other heat-responsive materials, such as certain plastics.They are also interested in modifying not just the visual properties of materials but their mechanical and acoustic qualities.
By doing so, they hope to manipulate properties like stiffness, flexibility, and even sound insulation, which could open up new possibilities in applications like prosthetics, where varying the stiffness in different areas of a part could improve comfort and functionality.In acoustic engineering, the method could enable better control over sound absorption or reflection, useful in designing speakers or soundproofing materials.“We believe that this technique is an important step towards using fewer materials while offering more versatile and expressive fabrication results,” concluded Zjenja Doubrovski, an assistant professor at TU Delft’s Faculty of Industrial Design Engineering.Subscribe to Our Email NewsletterStay up-to-date on all the latest news from the 3D printing industry and receive information and offers from third party vendors.
