While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.
Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant’s eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.
“This slippery periphery on the pitcher plant actually inspired our SLIPS product,” shares Mukherjee.
The pitcher plant’s innovation – which engineers are now copying – is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.
“We’re taking that same concept, but the roughness we’re using is just a common attribute of everyday plastics, which means maximal practicality,” comments Boreyko. “We aim to look with a keen eye at the world around us to take inspiration in order to solve our current problems.”
The research was fully funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech’s undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.
In collaboration with Bemis, they are looking to find the best match to put this solution into application. “It is a ‘Goldilocks’ problem – you have to find just the right size or type of packaging that is best suited,” enthuses Boreyko. “With small packaging, such as ketchup sachets, consumers apply enough physical pressure themselves to squeeze out the product, so slippery coatings aren’t vital. On the other hand if the pouch is too big, gravity does the work as it dominates the surface forces. We are looking for the ‘Goldilocks’ middle ground where the packaging is the right size for this solution to add benefit and provide strong appeal to get the product out faster and more efficiently.”
There are currently three companies testing with Bemis in order to discover the best route forward to licence the technology. It has a provisional patent and is looking for the perfect niche before achieving commercial translation.