Gas measurement for air plasma generators

Plasma, ionised gas, is the fourth state of matter after solid, liquid and gas. The sun, the aurora and lightning are all natural examples, while plasma technologies include advanced silicon etching machines, space propulsion systems and nuclear fusion reactors.

Atmospheric pressure plasma technologies can be used for chemical synthesis - scrambling molecules of nitrogen and oxygen in air, to produce nitrogen oxides and ozone. This mimics natural processes in lightning strikes and the atmosphere.

These air-derived reactive gases - reactive oxygen and nitrogen species (RONS) - have antimicrobial, bioactive and chemical effects. Their potential industrial applications span chemicals, hygiene, agriculture, food, bioprocesses and healthcare. Fourth State's mission is to make the biochemical benefits of RONS accessible - anywhere, anytime - with just air and electricity, using its patented Air Plasma technology.

One of the RONS generated by air-plasma, nitric oxide (chemical formula NO - not to be confused with nitrogen dioxide, NO2, or nitrous oxide, N2O) has been called a "miracle molecule" by scientists, due to its surprisingly important, diverse biological roles in animals, plants, fungi and microbes. NO is produced by almost every cell in the human body for a wide range of effects, including antimicrobial/anti-tumour action, control of blood flow and wound healing. Its discovery was awarded the 1998 Nobel prize in Physiology/Medicine. NO is used routinely as an inhaled drug, and was recently investigated as a COVID-19 rescue therapy. Numerous NO-based therapies are currently in development, but the limitations of conventional sources of NO - high pressure compressed gas cylinders and various chemicals - are a barrier to widespread use in healthcare and other applications.

Fourth State currently sells its portable air plasma generators to translational researchers (NOxLab R&D products) and third party integrators/OEMs (ModuNOx OEM solutions). These products provide customers with an easy, (cost-)effective, safe and sustainable source of NO (and/or other RONS if desired). Users of NOxLab R&D products can quickly establish correct settings for their intended RONS application in a laboratory, before scaling up to pilot- and full-scale deployment through ModuNOx OEM solutions.

This A4I project with the National Physical Laboratory (NPL) builds directly on previous collaborations, aimed at high-precision measurement of RONS generated by Fourth State's products. The first project between Fourth State and NPL was successfully delivered during the pandemic, through the Measurement for Recovery (M4R) programme - a case study on this project was recently published on NPL's website.