By University of Pittsburgh and ExOne
PITTSBURGH (April 27, 2020) … The ExOne Company, the global leader in industrial 3D printers using binder jetting technology, and the University of Pittsburgh, a leading public research university based in Pittsburgh, have partnered to develop reusable metal filters that fit into a specially designed respirator cartridge for sustainable, long-term protection against contaminants, such as COVID-19.
ExOne’s binder jetting technology is a high-speed form of 3D printing that can produce metal parts with specific porosity levels that can effectively filter out contaminants while allowing airflow.
ExOne has 3D printed respirator filters in two metals — copper and 316L stainless steel — and a range of porosity levels for use inside a unique cartridge designed by the Mechanical Engineering & Materials Science department in Pitt’s Swanson School of Engineering. Initial testing for airflow and filtration efficiency is currently underway, and the filters are being optimized with the goal of adhering to an N95 respirator standard.
In this video, Pitt Associate Prof. Markus Chmielus explains why binder jet 3D printing was critical to develop a fine metal filter that is a reusable, sterilizable solution and can eliminate waste as well as the need to continuously find reusable equipment.(Video courtesy of University of Pittsburgh Swanson School of Engineering)
“Our team has been working urgently to expedite this promising and reusable solution for medical personnel on the frontlines of fighting the COVID-19 pandemic,” said John Hartner, ExOne CEO. “Our customers routinely print porous metal filters for a variety of purposes, and we are confident that we’ll have a solution soon that can enable medical personnel to sterilize metal filters for repeated reuse, eliminating waste. Once approved, we can print these filters in a variety of sizes for respirators, ventilators, anesthesia masks or other equipment.”
“The advantage of binder jet 3D printing over other additive manufacturing methods for this filter application is the ability to utilize the porosity of the printed part and then fine tune it during the high temperature densification or sintering process to achieve optimum filtering and airflow performance,” said Markus Chmielus, Associate Professor of Mechanical Engineering and Materials Science at the Swanson School.
3D Printed Metal Filter Project Details
ExOne’s binder jetting technology uses an industrial printhead to selectively deposit a liquid binder onto a thin layer of powdered material, layer by layer, until a final object is formed. After 3D printing powdered metals, the object is then sintered in a furnace to dial in a specific level of porosity. While binder jetted metal is typically sintered to full density, some applications require a specific level of porosity, such as filters.
To test filters in different metals and porosities, Dr. Chmielus’ research group is using CT scanners to analyze the microstructure and porosity of the filters. Ansys, the global leader in engineering simulation, also based near Pittsburgh, is providing additional computer simulation support to analyze and optimize the performance of the filters.
While copper and stainless steel filters are currently being tested, copper has been known to have antibacterial properties since ancient times. The first recorded use of copper to kill germs was in the Edwin Smith Papyrus, the oldest known medical document in history, according to the Smithsonian. Many studies have proven copper’s disinfectant powers.
One landmark 2015 study, funded by the Department of Defense, revealed that copper alloys contributed to a 58% reduction in infections. COVID-19 research also suggests the virus dies faster on copper than on other surfaces.
About Swanson School of Engineering, University of Pittsburgh
The University of Pittsburgh’s Swanson School of Engineering is one of the oldest engineering programs in the United States and is consistently ranked among the top 50 engineering programs nationally. The Swanson School has excelled in basic and applied research during the past decade and is on the forefront of 21st century technology including sustainability, energy systems, bioengineering, micro- and nanosystems, computational modeling, and advanced materials development.
Approximately 120 faculty members serve more than 4,000 undergraduate and graduate students and Ph.D. candidates in six departments, including Bioengineering, Chemical and Petroleum Engineering, Civil and Environmental Engineering, Electrical and Computer Engineering, Industrial Engineering and Mechanical Engineering and Materials Science.
Director of Marketing and Communications
University of Pittsburgh Swanson School of Engineering
Pittsburgh, PA 15261
Source: University of Pittsburgh Swanson School of Engineering/ExOne