A patent-pending wet-mixing method developed by Purdue University researchers allows the even dispersal of electrically conductive particles within filament polymers for fused deposition modeling–based 3D printing. This new technology embeds sensing abilities Inside The 3D-printed part allows for rapid conversion of prototypes into functional components.
Traditional 3D printing makes prototypes with no sensing capabilities, explained a press release from Purdue, adding that sensors must be added to the part after the fact if assessments are to be made. This process is similar to adding sprinkles after cookies are baked. “The sprinkles exist only on the outside of the cookie. Traditional foil-type strain gauges, which are the most common strain sensors, are adhered to the surface of a printed part by an epoxy resin,” explained Brittany Newell, associate professor in the School of Engineering Technology in the Purdue Polytechnic Institute. “However, in this work the sprinkles are added throughout the cookie dough before baking. Sensing capabilities are an integral part of the printed component. This allows for sensing within the component. These sensors are smaller than sprinkles and can’t be seen without a microscope. Their tiny scale allows the printed part to maintain strength it would have otherwise sacrificed due to large sensors built in, while still achieving fully integrated sensing capabilities,” said Newell.
Newell, fellow associate professor Jose M. Garcia-Bravo, and Tyler Tallman, assistant professor in the School of Aeronautics and Astronautics in the College of Engineering, created the wet-mixing method with crucial contributions from Cole Maynard, who earned his PhD in August, and doctoral candidate Julio Hernandez.
Purdue’s wet mixing method ensures even distribution of particles in the filament. The press release stated that researchers and manufacturers can design parts with greater variety of shapes because the sensors are evenly distributed throughout the filament.
“The results from this work enable users to create complex 3D structures with embedded strain gauges, rapidly moving traditional prototype pieces into fully functional and structurally assessable parts,” Newell said. “A limitation of application of 3D printed parts has been in their durability. With this development, we can continually monitor the structural health of the part with the sensor embedded in the print.”
The technique greatly expands the electrical applications of 3D-printed parts and sensor designs, according to the researchers, and the electrical and mechanical properties can be “tuned” to optimize the sensor or part for a desired application.
Newell said that sensor conductivity is not the only benefit of Newell’s novel wet mixing process. “This work can be further expanded to add other particle types using the same wet-mixing method. This could include the addition of magnetic particles for electromagnetic fields, fluorescent particles, and other functionalities,” said Newell.
The study was published in July 2022 edition of the peer-reviewed journal Advanced Engineering Materials and in the 2020, 2021, and 2022 editions of the journal American Society of Mechanical Engineers Smart Materials and Adaptive Structures, and Intelligent Systems. The Naval Engineering Education Consortium has provided funding to the researchers. This program is part of the NAVSEA warfare centres and aims to foster partnerships between the Navy, higher education institutions, and the military.
The researchers disclosed the innovation to the Purdue Research Foundation Office of Technology Commercialization, which has applied for a patent on the intellectual property. Dhananjay Swak is available for industry partners who wish to further develop the innovation. [email protected]Refer to reference number 69740.