As part of his research in the school's Environmental NMR Center, Simpson utilizes a 3D printer, which typically uses melted plastic resin for the building material. When plastic prices rose too high, the professor looked for other resin sources and stumbled across cooking oil.
Discovering that the molecules making up the plastic resin were similar to those found in oil, the scientist decided to send out feelers to local fast-food restaurants to request their used cooking oil. McDonald's was the only restaurant that agreed to Simpson's request.
Part of the scientist's research requires an analytical tool, known as the NMR spectrometer, which is similar to an MRI machine. In an attempt to bridge the gap between medical studies and the environment, Simpson explained that he and his colleagues used the spectrometers to look inside tiny living organisms and understand their biochemical response to their changing environment.
The lab brought in a 3D printer in the hopes that they could build custom parts that would help keep the organisms they studied alive in the NMR spectrometer.
After a local McDonald's in Toronto gave the scientist and his team 10 liters of used cooking oil, they set to work filtering out food particles and converting it into resin to use in the 3D printer.
The team of researchers was able to print a butterfly with incredibly detailed features as small as 100 micrometers in size. Simpson described the butterfly as structurally stable and rubbery to the touch. He added that it didn't break apart at room temperature, also noting that it was biodegradable.
Terri Toms, the McDonald's franchisee who agreed to give the restaurant's used oil to the team, explained why the restaurant decided to donate it.
"I was impressed by the research initiative and happy to contribute to something that could possibly be helpful to future generations," she said.
Another spokesperson for the fast-food chain commented that the experiment was a "great initiative."
In the paper that Simpson and his colleagues published following the successful experiment, the scientists noted that it costs millions of dollars every year for fast food restaurants to process waste, including cooking oil.
"Most recycled waste cooking oil is currently used in the production of soap and biodiesel. It may be transformative for recycling programs if high-value commodities [such as resin] can be manufactured directly from it."The team hopes their results will get noticed by the industry.