Plastic butterfly printed with cooking oil-based resin. (Credit: Don Campbell)
A team of researchers at the University of Toronto Scarborough (U of T) have successfully turned cooking oil from McDonald's into a biodegradable 3D printing resin.
The research addresses environmental concerns around commercial and household cooking oil waste by turning old cooking fat into a lower-cost, high-resolution alternative to conventional 3D printing resins.
Andre Simpson, a professor at U of T Scarborough’s department of physical and environmental sciences who led the development, discovered while tinkering with his 3D printer that the molecular structure of cooking fat was similar to that of commercial resins. Using waste from a local McDonald's restaurant, Simpson and his team were able to make 420 millilitres of printable resin using one litre of cooking oil which was acrylated in a one-step chemical process. According to a report by UoT, all but one of the chemicals used to make the resin can be recycled, which meant the material could be produced for around 300 USD per tonne. The researchers suggest that the cost is significantly cheaper than conventional resins which are made with fossil fuels in a multi-step process and can cost around 500 USD per litre.
The team used a stereolithography process to successfully print a butterfly with a feature resolution of 100 microns, showing features down to 100 microns and thermal stability.
Potential benefits include the reduction of waste and carbon emissions, while the material was also found to biodegradable. Researchers tested a printed object by burying it in soil and in just two weeks, the part lost 20 percent of its weight as microbes started to naturally break down. Simpson also suggested that creating a high value solution could remove some of the financial barriers faced by restaurants when recycling waste cooking oil.
