Since the invention of the air purifier, scientists and designers have attempted to address issues about indoor air quality by harnessing natural processes of purification, while also trying to assist in the production of machines that are not ugly boxes festooned with grilles.

The Andrea, invented by French designer Mathieu Lehanneur and Harvard professor David Edwards, employs an award-winning filtration system designed to absorb and purify toxic gases, such as formaldehyde, in home and office environments through the natural absorptive and metabolic properties of living plants.

In addition it is unobtrusive enough to sit in a living room without looking out of place because it appears to be a plant in a plastic dome.

Meanwhile, the O2 air purifier by Tian Lingrui relies solely on plants to improve air quality.

The saucer-like machine is designed to accelerate the process of photosynthesis while also reminding owners to water their houseplants.