Wisconsin is famous for its cheese and soon may be famous for a new way to slice it. Xiaochun Li, a UW-Madison mechanical engineering professor, is using ultraviolet light lasers to slice cheese into Bucky Badgers, UWs and any other shape imaginable. Li believes his novel invention has great commercial appeal, offering a precise, clean and efficient way to slice cheese.
Traditionally, cheese is sliced with a stationary blade, similar to a large cylindrical cheese grater, explained Scott Rankin, a UW-Extension dairy foods expert.
\Cheese undergoes a lot of strain during slicing, and it also generates a lot of waste,"" Rankin said.
Thinly slicing cheese is also a problem, according to Li, because cheese easily tears and sticks to the blade.
About 10 years ago, scientists experimented with lasers to cut cheese, hoping to eliminate many of the problems with mechanical slicing, Li explained. The lasers, however, generated too much heat, burning and melting the cheese.
The solution, Li says, is to use an ultraviolet light laser. The laser emits pulses of photons, which are high-energy particles of light that break the cheese apart.
""The photon has a higher energy than the bound cheese molecules,"" he said. ""The laser breaks the bonds, and quickly pushes cheese molecules out."" The entire process lasts only nanoseconds.
""It's so short that it generates almost no heat, and it's too quick for heat to diffuse into the cheese,"" Li said.
Think of when you shake hands with someone who has been outside on a cold day, Li explained. You can feel the cold. However, if you only shook hands with them for a nanosecond, a billionth of a second, you would not feel a thing.
Because the lasers are computer-guided, it can be reconfigured to cut any shape, and the high-energy laser kills bacteria. These are big advantages for manufacturers, Li said.
""The procedure is flexible. It can shave cheese in any shape ... and because bacteria are killed, the cheese can be stored for longer periods of time,"" Li said.
Currently, the procedure is too slow for commercial uses. With a laser several times more powerful than the one currently used, speed will increase, and Li hopes to use the lasers on meat, fruit, breads and any other heat-sensitive material. He also wants to form a laser food-processing consortium to speed the research.
""Right now, we're just waiting for some good news,"" Li said, ""We want more research, more students. But a year and a half ago, I didn't know [this was possible].\
