Computer aided design (CAD) files, the most common vehicle by which complex shapes and parts are delivered digitally, are a key part of the quickly evolving 3D printing field, which grew to $7.3 billion in 2018 and is set to double in the next four years.
However, CAD methods have not evolved fast enough to keep pace with advances in printing and the increasing sophistication of hackers and counterfeiters set on disrupting the 3D printing supply chain or stealing intellectual property.
Nikhil Gupta and Ramesh Karri, NYU Tandon professors of mechanical and aerospace engineering and of electrical and computer engineering, respectively, along with Nektarios Tsoutsos, assistant professor of electrical and computer engineering at the University of Delaware, have received a National Science Foundation (NSF) award of $400,000. Their work will advance a novel system that allows new possibilities and functionalities in CAD files.
The researchers are perfecting a method of converting CAD files to a frequency domain, just like a digital sound file, in a way that would allow end users much more flexibility in how they slice and dice the files for printing.
“The functionality that we would like to add to these files is the ability to search for them,” said Tsoutsos. “This seems obvious—it’s like searching for an e-mail that has a keyword. Unfortunately, CAD files do not support this functionality yet, because when they were first defined decades ago, no one thought that was possible.”
Imagine that you have a CAD file for a component part of a car or airplane, and you want to search for parts with similar components, such as gears. The team aims to develop a system that will make this possible—which could benefit people who use CAD across a wide variety of industries.
“This is a timesaver because you can find all the files that have similar characteristics, and it is going to have a big impact in industries like aerospace, medical and automobile industries,” said Tsoutsos. All these industries are impacted by 3D printing technologies.
The NSF award will allow the team to further research ways of converting files to a frequency domain using lossless algorithms — a class of data compression algorithms that allows the original data to be perfectly reconstructed from the compressed data — and let people who receive the files extract specific design features in a way that is not feasible in the current CAD file formats. Transformation to the frequency domain opens up possibilities for developing new compression and encryption methods.
“We are going to convert the 0s and 1s into an audio file just like the MP3 files that you have on your phone,” said Tsoutsos. This enables search functionality because experts already know how to search for patterns in audio files. Apple’s Siri and the smartphone app Shazam, for example, can search audio files. Now, the NYU and UD researchers will do something similar with CAD files.
Complex mathematical methods such as Fourier transforms enable the conversion and search.
“New generative design and multi-criteria optimization methods are revolutionizing the way designs are developed in the industry,” said Gupta. “These methods are also automating the design process, leading to thousands of design iterations in a short time. The new search, compression, and encryption methods will help designers deal with these files more efficiently and securely.”
“Development of these new capabilities open doors to a host of possibilities beyond the critical design and search functions” Karri added.
Students will learn from the project in the form of student hacking competitions to take place in 2020.
Adapted with permission from the New York University Tandon School of Engineering.