More than 80% of children in the United States suffer from middle ear infections (also known as otitis media). Researchers have created a 3D-printed miniaturized device that can inactivate Pseudomonas Aeruginosa, the common bacterium responsible for this infection.A microplasma jet array is a device that generates plasma. It's composed of reactive molecules and charged particles, which have previously been shown to kill various pathogens. Jungeun Won is a Boppart graduate student who said that plasma technology was the first to treat middle ear infections. "Normally, treatment involves antibiotics or surgical intervention."Two problems arise from antibiotics. The first is that antibiotics are not effective in over 30% of patients with acute infections. Their use can increase antibiotic resistance as the bacteria forms biofilms, which attach to the ear's surface.Helen Nguyen (IGOH), a Ivan Racheff Professor of Civil and Environmental Engineering, stated that biofilms are dense and make it difficult for antibiotics to penetrate. "We thought that by disrupting the structure of biofilms, we could increase antibiotic penetration."Researchers built a model of the middle-ear to test the microplasma array. The researchers used an excision of the rat's eardrum to test the antimicrobial effects on bacteria behind the eardrum.Won stated that different treatment times were used to kill the bacteria. Won suggested that the treatment took 15 minutes or more. "We also checked the tissue for any signs of damage, but there was no obvious evidence."Nguyen stated that microplasma is believed to disrupt the biofilm by affecting the bacterial cell membrane. We have only indirect measurements to support our hypothesis, but we will continue to investigate it."The thickness of the rat's eardrum is 30% less than that of a human. However, these results indicate that microplasma could be used to treat middle-ear infections in humans.Stephen Boppart (Grainger Distinguished Chair for Engineering) said that middle ear infections and over-prescriptions of antibiotics are major clinical challenges and require new treatment technologies and solutions. He is also a doctor.Researchers are currently developing a smaller, earbud-shaped jet array to allow for longer exposure times. The researchers will also test the devices in animal models with biofilms of other bacteria that causes middle ear infections such as Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to see if the treatment works with these bacteria. The plasma technology will also be closely monitored to ensure there are no structural or functional tissue injuries.###The study was conducted in collaboration with J. Gary Eden, Intel Alumni Endowed chair in Electrical and Computer Engineering and Stephen Boppart a Grainger Distinguished chair in Engineering with appointments in the Departments Electrical and Computer Engineering and Bioengineering."Inactivation of Pseudomonas Aeruginosa by microplasma array for treating otitis media" is published in npj Biofilms. It can be found at 10.1038/s41522-021-00219-2. This work was supported by the National Science Foundation, U.S. Air Force Office of Scientific Research and the National Institutes of Health.