A prototype plasma jet engine can generate the same amount of thrust as a commercial jet engine using only air and electricity.

Humans depend on minerals as their primary source of energy. But fossil fuels are the largest source of greenhouse gas emissions, leading to negative respiratory effects and destruction due to global warming.

Researchers from the Institute of Technological Sciences of Wuhan University demonstrated a prototype device that uses microwave air plasma for jet propulsion.

“The motivation behind our work is to help solve global warming caused by people using fossil fuel internal combustion engines to power vehicles like cars and airplanes. Since there is no need for fossil fuels with our engine design, there are no greenhouse gases and carbon emissions that cause global warming.”said Zhou Tang, a professor at Wuhan University.

Plasma is the fourth state of matter, consisting of a collection of charged ions, in addition to the solid, liquid, and gaseous state. It occurs naturally in places such as the sun’s surface and lightning, but can be produced. The researchers created a plasma jet by compressing air to high pressure and using a microwave oven to ionize the compressed air stream.

This method differs significantly from previous attempts to create jet plasma engines. Other plasma jet engines, such as NASA’s Dawn space probe, use xenon plasma, which cannot overcome the friction in the Earth’s atmosphere and is therefore not powerful enough for use in air transport. Instead, the new plasma jet engine produces high-temperature, high-pressure plasma in situ using only injected air and electricity.

A prototype plasma jet device can lift a 1-kilogram steel ball over a 24 millimeter diameter quartz tube, where high-pressure air is converted into a plasma jet by passing it through a microwave ionization chamber. On scale, the corresponding thrust pressure is comparable to a commercial jet engine.

By producing more of these engines with powerful microwave sources, the prototype could be scaled up to a full-size jet. The authors try to increase the efficiency of the device to achieve this goal.

“Our results showed that such a microwave air plasma jet engine could be a potentially viable alternative to a conventional fossil fuel jet engine.”said Tan.