have invented a super-slippery material inspired by the carnivorous pitcher
... a new material takes a cue from one of the plant world's few
meat-eaters: the carnivorous pitcher plant Nepenthes. The plants prey
on insects, whose oily feet normally allow them to walk up walls. But
pitchers' tube-shaped leaves have microscopic bumps that hold a thin
layer of water in place. The water repels the oils, sending hapless
insects slipping straight into their gaping mouths.
"They just step on the rim, and immediately slide into the
digestive juices," Aizenberg says.
Aizenberg realized that with the right choice of lubricating liquid,
the pitcher plant's strategy could be adapted to repel virtually anything.
The researchers started with a textured substrate, which could
be almost anything that is rough on the nanoscale, Aizenberg says. One
good choice is Teflon, a fibrous material that is widely thought to
be super-slippery itself.
Their most slippery surface resulted when they added a layer of
the perfluorinated fluid 3M Fluorinert FC-70, manufactured by the firm
3M, to Teflon. The liquid oozed into all the pores in the Teflon, and
left a nanometres-thin layer of liquid at the top. The material still
feels dry to the touch, and other liquids simply hydroplane off the
surface, like a car sliding off a wet road. The team calls the material
'slippery liquid-infused porous surfaces,' or SLIPS.
"We call it SLIPS, because everything does," Aizenberg
NewScientist has the story: Link
- via Popsci