Plasma sterilization and disinfection

Team Lead: Lakshminarayana Rao, Anand M Shivapuji
Email: narayana@iisc.ac.in, anandms@iisc.ac.in

I. Rapid Plasma Sterilization of PPE (RaPS)

At the Center for Sustainable Technologies, IISc, we have developed rapid plasma sterilization of Personal Protective Equipment (PPE), specifically for masks used by medical first responders. In this crisis, with shortage of such masks, our device permits reuse of the masks with necessary disinfection.

As COVID-19 will remain with us for the foreseeable future (according to WHO) it becomes necessary to use masks in our day-to-day life to prevent/minimize the spread. This is not only good for individual citizens but also good for the country and the world so that we all can help in the fight against COVID-19 by not spreading it. With challenges in primary health care facilities, particularly in many regions of the South Asia and Africa, sterilization of PPEs provides significant protection to the medical fraternity.

We have developed low-cost equipment which is easy to deploy at scale, which requires only atmospheric air and electric power as input. Figure 1a shows a picture of plasma ozone generator and figure 1b shows a picture of our RaPS system.

Figure 1a: Photo of the developed plasma Ozonators

Figure 1 b: Photo of the RaPS system

Salient features of RaPS

  • RaPS uses atmospheric air to generate ozone which is the most powerful known disinfectant and does not require any special gas preparation system.
  • RaPS is equipped with internal humidity control and gas circulation system to ensure efficient disinfection. Also, it comes with residual ozone detectors, gas evacuation and purge systems.
  • RaPS can disinfect PPEs in a short time span of 30 minutes and eliminate generation of bio-medical waste, which otherwise needs incineration.
  • Ozone is known to kill a wide range of bacteria and viruses including, adenovirus type 3/11, human norovirus, herpes simplex virus, vesicular stomatitis virus, encephalomyocarditis virus, GDVII virus, Staphylococcus aureus, Pseudomonas fluorescens, Salmonella typhimurium, enteropathogenic Escherichia coli, Vibrio cholerae, Shigella flexneri, mouse coronavirus, poliovirus, rhinovirus type 1A/14, vaccinia virus, yellow fever virus, etc.
  • Any residual ozone, after disinfection of PPEs, is detected and destroyed within our RaPS equipment.

Team leader: Lakshminarayana Rao
Team members: H N Chanakya, S Dasappa and Anand M Shivapuji
Research staff: Manju D K and Leelesh

II. Plasma Ozonators for Disinfection of Spaces (PODS)

At the Center for Sustainable Technologies, IISc, we have developed a high throughput ozone generator which works using cold plasma technology. Ozone generated from the ozonator shall be retrofitted for disinfection of spaces, both mobile and stationary. Figure 1a shows a picture of plasma ozone generator and figure 1b shows a field installation of the developed ozone delivery system.

Figure 1a: Photo of the developed plasma ozonators

Figure 1b: Photo of the field installed ozone delivery system

Salient features of PODS

  • The PODS system works with atmospheric air as the feed gas to generate ozone which is the most powerful known disinfectant and does not require any special gas preparation system.
  • The technology is modular and can be scaled to achieve disinfection of small rooms (10’ x 10’) as well as large spaces (50’ x 50’) in a short span of 30 minutes to few hours, depending on the volume of the disinfecting space.
  • Ozone being gaseous in nature, as used in the current application, has the ability to reach every nook and corner of any space, open or otherwise, unlike the current atomized spray-based chemical systems. As such, Ozone based disinfection philosophy ensures guaranteed disinfection of even remote and inaccessible regions of spaces.
  • The compact PODS system is available both as stationary models and mobile units.
  • Ozone is known to kill a wide range of bacteria and viruses including, adenovirus type 3/11, human norovirus, herpes simplex virus, vesicular stomatitis virus, encephalomyocarditis virus, GDVII virus, Staphylococcus aureus, Pseudomonas fluorescens, Salmonella typhimurium, enteropathogenic Escherichia coli, Vibrio cholerae, Shigella flexneri, mouse coronavirus, poliovirus, rhinovirus type 1A/14, vaccinia virus, yellow fever virus, etc.
  • PODS can be used for disinfecting any spaces such as trucks/containers filled with fruits, vegetables & cargo, hospital rooms, buildings and any closed spaces.
  • To address the limitation of exposure to residual ozone, the PODS system is equipped with residual ozone destruction device, residual ozone detectors and gas purge systems.
  • With no use of chemicals, organic or otherwise, as is the current practice, and flushing of residual ozone, there are no chances of residual side-effects.

Team leader: Lakshminarayana Rao and Anand M Shivapuji
Research staff: Manju D K and Leelesh

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