Researchers in the US have developed a method to track the origin of 3D printed items by identifying machines by their unique ‘hot end’, reducing the risk of 3D printer users tampering with national security and intellectual property.
3D printing is transforming everything from fashion and healthcare to transportation and toys. But this rapidly evolving technology, also known as additive manufacturing, can pose a threat to national security and intellectual property rights.
To reduce the illegal use of 3D printers, Zhan Peng Jin, associate professor in the Department of Computer Science and Engineering at the University of Buffalo, is developing a way to trace the origins of 3D printed items.
Jin was concerned that as long as people have the digital design for an item – which can be downloaded from the Internet, sometimes as open-source material – they can print anything they want, from computer parts and toys to more dangerous objects. such as fully functional pistols and assault rifles.
“So what’s the best way to protect our intellectual property from someone else printing the same design with their own printer?” Jin asked. “We wanted to find something internal. What are the inherent signatures printed by my own 3D printer instead of another 3D printer? “
University at Buffalo tech can identify machines by their unique ‘hot end,’ could aid intellectual property, security.p
3D printers build three-dimensional objects by adding successive layers of print material according to the digital design for a 3D model. Each 3D printer has an “extruder” that propels the building material.
The hot end of the extruder then melts the material and places it on the print bed to build the model. The researchers focused on this part as part of their research.
This is because the hot end of each extruder has its own unique heating properties, which affect the precise construction of the 3D model. Such thermodynamic properties can identify the specific extruder and thus the model of a 3D printer, as unique as a human fingerprint, or what Jin has called a “Thermo Tag”.
For the investigation, Jin compared the process to using a laptop to write a letter. Because software exists that can track keystrokes, an observer can see every step in the letter, including the writer’s unique writing style.
Likewise, due to the unique properties of each 3D printer’s extruder, a researcher can investigate the specific way a user created a 3D printed object and compare that against a database of different extruders until they make a match.
From there, once the authorities identified the model printer, they could track down the model purchaser if, for example, they had used the printer to build an illegal assault rifle.
Diagram showing components of a 3D printer
Jin and his team found that by examining and comparing the Thermo Tag features of 45 different extruders of the same model, they were able to identify the source printer with 92 percent accuracy. “This Thermo Tag acts like the fingerprint of the 3D printer.
When you print a new product you can use watermarks, ” said Jin, noting that they can use the watermark to invisibly insert information such as the printer manufacturer, label and serial number into the product.
“So that would make this watermark of this product unique.” According to Jin, it is possible that someone can replace their extruder to avoid detection. “That’s why it’s important to create a database of these parts for comparison,” he said.