When farmers spray their crops with pesticides and other treatments to help ensure their survival, 98 per cent of those chemicals bounce right off the plants and end up in the groundwater as pollution. It's a waste, and harmful to the environment, so researchers at MIT came up with a cheap but effective way to instead make those chemicals stick to crops. Plants are naturally hydrophobic, which means that liquids tend to bounce right off them. As a result, blasting them with liquid pesticides requires a tremendous amount of chemicals so that the two per cent that actually sticks actually effectively keeps pests at bay. What the researchers at MIT came up with was a way to make these liquid pesticides actually stick to plants and leaves upon application.
The new application technique uses two different polymer additives that are introduced as the pesticide is being sprayed, but the real trick is that one of the additives is first given a positive charge, while the other is given a negative. When the oppositely-charged drops meet on the surface of a plant they end up creating a hydrophilic water-attracting film that sticks to the leafs, trapping other droplets as well.
Not only is it a clever solution to a problem that affects crops around the world, the biodegradable additives required are cheap to produce, and only minor upgrades are needed to make pesticide equipment work with the new application technique. It also means farmers can use far less chemicals to treat their crops, increasing profits and reducing the harmful affects on the environment.