For Hawkesbury residents who have chased a stubborn lump around a mug of chocolate milk, shaken a protein drink or a powered home made cappuccino until their arms ache, scientists are investigating a possible solution: controlling static electricity.
Researchers from RMIT University and Riga Technical University in Latvia have demonstrated a way to control the static charge left behind when two surfaces touch and separate.
The discovery could eventually help manufacturers reduce clumping in powders, including protein supplements, chocolate malt drinks and coffee.
However, the work remains at an early stage. The researchers tested plastic films in a laboratory, and food powders have yet to be put to the test.
Static electricity can develop as powder particles rub and tumble during manufacturing, packaging and pouring. The resulting charge can make particles cling together, contributing to those unwelcome lumps.
Study co-leader Dr Peter Sherrell, from RMIT’s School of Science, said applying an electric field during processing could potentially prevent that charge from building up.
“In principle, we could apply a small electric field across powders as they move,” he said.
“That stops them charging up, so they don't get electrostatically ‘stuck’ to each other.”
The team pressed polystyrene films together and pulled them apart 500 times while applying external electric fields.
By changing the field, researchers could control how much charge remained and whether it was positive or negative. They could also remove the charge.
The findings suggest manufacturers may eventually be able to tailor static control to particular materials and processes.
For the Hawkesbury’s agricultural community, one potential application is seed handling. Dr Sherrell said different seed sizes or species could require different settings on processing equipment to manage static charge.
Other possible applications include electronics manufacturing, filters and controlling where particles stick.
Those industrial uses still require further research. The technique has not been demonstrated on industrial equipment, and changing charge during a running process remains a proposed application.
For food powders, the next task is to establish how strong an electric field needs to be, how long it should be applied and where it would work best during production.
The research was led jointly with Dr Andris Šutka of Riga Technical University and published in Nature Communications.
A smoother morning shake may still be some way off, but the findings offer a promising direction for tackling a familiar kitchen frustration.
