'Sticky Tape' for Water Droplets Prevents Water From Rolling Off Surfaces

Researchers have developed a nanostructure capable of trapping tiny water droplets and preventing them from rolling off surfaces -- even when turned upside down.

The discovery, outlined in the journal Chemistry of Materials, uses raspberry particles -- so named because of their appearance -- which mimic the surface structure of some rose petals.

"Water droplets bead up in a spherical shape on top of rose petals. This is a sign the flower is highly water repellent," Andrew Telford, a chemistry professor from the University of Sydney, said in a statement.

The reason lies in the rose petal's surface, which the team replicated by assembling raspberry particles using spherical micro- and nanoparticles that trap the water droplets.

"Raspberry particle films can be described as sticky tape for water droplets," Telford said.

The invention carries with it a number applications, including reducing condensation in airplane cabins or allowing for the rapid processing of simple medical tests on free-standing droplets.

Thinking broader, the researchers envision applying the nanotechnology to control how surfaces everywhere interact with water.

"This means we will be able to design a surface that does whatever you need it to do," Telford said, including "a surface that stays dry forever, never needs cleaning or [is] able to repel bacteria or even prevent mold and fungi growth."

Going the other direction, Telford said structure can be tweaked to create a surface across which water spreads especially fast.

"This could be used on quick-dry walls and roofs which would also help to cool down houses."

Either way, the researchers say the discovery is potentially viable on a commercial level.

"Our team's discovery is the first that allows for the preparation of raspberry particles on an industrial scale and we are now in a position where we can prepare large quantities of these particles without the need to build special plants or equipment," Telford said.