Dr. Peter Eng, working with University of Chicago Medical Center (UCMC) Executive Director of Perioperative and Procedural Services Jon Brickman, and with help from GSECARS’ Mike Proskey and Dr. Joanne Stubbs, has developed a safe and efficient method for disinfection of N95 masks for re-use by UCMC staff.  Existing high-powered UV disinfection units at the hospital were temporarily repurposed by Eng and Brickman to disinfect an array of masks instead of operating rooms and patient care rooms.  This unit is now in service at The University of Chicago Hospital, and has a disinfection throughput of thousands of masks per day.  The downside of this mask disinfection approach is that these full room systems are expensive (> $100K) and are primarily designed and purchased to disinfect full rooms.  Re-tasking these units for mask disinfection deprives the hospital of their use for room scale disinfection but quickly addresses an ongoing urgent need for PPE preservation.

Once the room based system was being utilized at UCMC, the need for greater availability of UV disinfection systems became clear. Eng therefore designed an entirely new self-contained unit comprised of inexpensive, off-the-shelf components. The new prototype was completed on April 17th and delivered to UCMC a few days later where the system is now going through validation and usability testing.

Eng assembled a team of University of Chicago scientists, medical professionals and engineers to help develop the new prototype. Using light field modeling and measurements, this team helped develop an optimized arrangement of lamps which provides full irradiation and disinfection of all N95 respirator surfaces in under a minute. The growing need for new or disinfected PPE in hospitals is widely understood at this point, but other unexpected industries would benefit from the ability to quickly disinfect large quantities of N95 masks: manufacturing sites, nursing facilities, first-responder districts, and military facilities. This need is expected to be long-term until a COVID-19 vaccine can be widely implemented.

GSECARS is an NSF funded facility, Sector 13 at the Advanced Photon Source, Argonne National Laboratory.

N95 Disinfection Project Contacts


Peter Eng

(630) 252-0424

Mike Proskey

(630) 252-0428

Joanne Stubbs

(630) 252-0427

Eng’s full room system layout showing masks mounted to movable frames that are illuminated by three powerful UV-C emitter towers. Masks are mounted to frame made of copper pipes with screws spaced 2” vertically. The mask straps are stretched over the screws in a non-overlapping chevron pattern. Eng built five mask frames that were delivered to the UCMC on April 1st. Each frame holds 32 masks and the wearer’s name tag. They can be rolled in and out of the various work spaces needed to start and complete the disinfection process.

 Prototype of small scale, self contained disinfection unit.