Tag: plasma technology

An ‘Invisible Mask’ Air Curtain that Kills Viruses, Blocks 99.8% of Aerosols

Taza Aya’s Worker Wearable Protection device keeps airborne virus particles from reaching a workers mouth and nose with an air curtain. That air is pre-treated to kill any viruses. Image credit: Jeremy Little, Michigan Engineering

An air curtain shooting down from the brim of a hard hat can prevent 99.8% of aerosols from reaching a worker’s face. The technology, created by University of Michigan startup Taza Aya, potentially offers a new protection option for workers in industries where respiratory disease transmission is a concern.

Independent, third-party testing of Taza Aya’s device showed the effectiveness of the air curtain, curved to encircle the face, coming from nozzles at the hat’s brim. But for the air curtain to effectively protect against pathogens in the room, it must first be cleansed of pathogens itself. Previous research by the group of Taza Aya co-founder Herek Clack, U-M associate professor of civil and environmental engineering, showed that their method can remove and kill 99% of airborne viruses in farm and laboratory settings.

“Our air curtain technology is precisely designed to protect wearers from airborne infectious pathogens, using treated air as a barrier in which any pathogens present have been inactivated so that they are no longer able to infect you if you breathe them in,” Clack said. “It’s virtually unheard of – our level of protection against airborne germs, especially when combined with the improved ergonomics it also provides.”

Fire has been used throughout history for sterilisation, and while we might not usually think of it this way, it’s what’s known as a thermal plasma. Nonthermal, or cold, plasmas are made of highly energetic, electrically charged molecules and molecular fragments that achieve a similar effect without the heat. Those ions and molecules stabilize quickly, becoming ordinary air before reaching the curtain nozzles.

Taza Aya’s prototype features a backpack, weighing roughly 10 pounds (4.5kg), that houses the nonthermal plasma module, air handler, electronics and the unit’s battery pack. The handler draws air into the module, where it’s treated before flowing to the air curtain’s nozzle array.

Taza Aya’s progress comes in the wake of the COVID pandemic and in the midst of a summer when the U.S. Centers for Disease Control and Prevention have reported four cases of humans testing positive for bird flu. During the pandemic, agriculture suffered disruptions in meat production due to shortages in labour, which had a direct impact on prices, the availability of some products and the extended supply chain.

In recent months, Taza Aya has conducted user experience testing with workers at Michigan Turkey Producers in Wyoming, Michigan, a processing plant that practices the humane handling of birds. The plant is home to hundreds of workers, many of them coming into direct contact with turkeys during their work day.

To date, paper masks have been the main strategy for protecting employees in such large-scale agriculture productions. But on a noisy production line, where many workers speak English as a second language, masks further reduce the ability of workers to communicate by muffling voices and hiding facial clues.

“During COVID, it was a problem for many plants – the masks were needed, but they prevented good communication with our associates,” said Tina Conklin, Michigan Turkey’s vice president of technical services.

In addition, the effectiveness of masks is reliant on a tight seal over the mouth and noise to ensure proper filtration, which can change minute to minute during a workday. Masks can also fog up safety goggles, and they have to be removed for workers to eat. Taza Aya’s technology avoids all of those problems.

As a researcher at U-M, Clack spent years exploring the use of nonthermal plasma to protect livestock. With the arrival of COVID in early 2020, he quickly pivoted to how the technology might be used for personal protection from airborne pathogens.

In October of that year, Taza Aya was named an awardee in the Invisible Shield QuickFire Challenge – a competition created by Johnson & Johnson Innovation in cooperation with the U.S. Department of Health and Human Services. The program sought to encourage the development of technologies that could protect people from airborne viruses while having a minimal impact on daily life.

“We are pleased with the study results as we embark on this journey,” said Alberto Elli, Taza Aya’s CEO. “This real-world product and user testing experience will help us successfully launch the Worker Wearable in 2025.”

Source: University of Michigan

Researchers Test Plasma Energy to Accelerate Healing of Achilles Tendon

Achilles tendon injury. Credit: Scientific Animations CC0

The Achilles tendon, although considered the toughest in the body, can rupture, with many such injuries involving sports enthusiasts in their 30s or 40s. Surgery might be required, and a prolonged period of rest, immobilisation, and treatment can be difficult to endure. Researchers in Japan have developed an approach using irradiation with plasma to accelerate healing.

A research team led by Osaka Metropolitan University Graduate School of Medicine’s Katsumasa Nakazawa, a graduate student in the Department of Orthopedic Surgery, Associate Professor Hiromitsu Toyoda, and Professor Hiroaki Nakamura, and Graduate School of Engineering Professor Jun-Seok Oh has focused on non-thermal atmospheric-pressure plasma (the electrically-charged gas such as found in a neon lamp – not blood plasma!) as a treatment method for tendon repair.

Their study, published in PLOS ONE, is the first to show that such plasma irradiation can accelerate tendon repair.

The team ruptured then sutured the Achilles tendon of lab rats. For one group of rats, the sutured area was irradiated with a helium plasma jet.

The plasma-irradiated group exhibited faster tendon regeneration and increased strength at two, four, and six weeks after surgery compared to the untreated group.

“We have previously discovered that irradiation of non-thermal atmospheric-pressure plasma has the effect of promoting bone regeneration. In this study, we discovered that the technology also promotes tendon regeneration and healing, showing that it has applications for a wide range of fields,” Professor Toyoda declared. “Combined with current tendon treatments, it is expected to contribute to more reliable tendon regeneration and shorter treatment time.”

Source: Osaka Metropolitan University

Atmospheric Plasma Device Boosts Bone Regeneration

Photo by Zoltan Tasi on Unsplash

Scientists in Japan have developed a plasma device that promotes bone regeneration in fractures.

Unlike blood plasma, plasma here refers to the fourth state of matter, effectively a highly ionised gas, which has been long investigated as an effective surgical scalpel which cauterises tissue as it cuts. Other recent applications of plasma technology include surface sterilisation.

Now, a new type of plasma device, termed non-thermal atmospheric pressure plasma (NTAPP), was successfully tested in healing of bone fractures in animal bone defect models. It is cooler than most plasmas that are typically used. In a study published in PLOS ONE, researchers from Osaka City University detailed their findings using the technology in this world-first application.

Acceleration of cell growth
“NTAPP is considered a new therapeutic method,” said first author Akiyoshi Shimatani, “as it has been shown to accelerate cell growth when applied at low enough levels.” He explained that in an ambient atmosphere it can generate highly reactive oxygen and nitrogen species (RONS) which can be directly exposed to tissues.

Indirect treatments have shown the potential advantages of plasma in supporting the creation of stem cells that cause reactive oxygen species and in inducing osteogenic differentiation and bone formation, however, as the team points out there is no report on directly using NTAPP for bone fracture therapy. “Direct exposure of NTAPP is a key part of this study” states Jun-Seok Oh, professor at the OCU Graduate School of Engineering and advisor to the study, “It required a device specifically designed to generate and deliver RONS to areas of the bone defect ‘effectively’.”

The research group developed a pencil-like plasma device that can effectively generate and deliver RONS to an animal model with a well-established critical bone defect, allowing the team to search for the optimal exposure conditions. Comparing groups that were treated with NTAPP for 5, 10, and 15 minutes to control groups with no plasma administered, micro-CT images at eight weeks showed the 10-minute treatment time as the most successful bone regeneration with 1.51 times larger bone volume than the control group.

Since micro-CT images could not determine whether a bone defect has been filled with new bone, tissue or both, the team also ran a histological analysis and confirmed bone defects in the groups treated with plasma were in fact filled with new bone, and had no tissue or gaps like the control groups.

Precision therapy
The biological effect of plasma, like other therapies, depends on the treatment dose delivered into the targets. Although future research will be needed to clarify why the study saw the most bone regeneration during the 10-minute treatment period, surface wettability is understood to promote greater cell spreading and adhesion to biomaterials and implants. Hiroaki Nakamura, professor at the Graduate School of Medicine explained: “We wondered if something similar was occurring where we saw a strong generation of new bone. And we found that compared to the control group, bone surface of the plasma-treated group as statistically and significantly more hydrophilic.”

The research team hopes the plasma device they developed can be applied for surgical use.

Source: Osaka City University