Creator: Joo Sang James Lee
Supervisor: Peter Yeadon
This study examines how light-emitting smart materials might be used to solve an environmental problem. The project, called Shellon (Shell+Crayon), is a set of phosphorescent crayons made from substantial amounts of oyster shell waste that’s found along the coast near Tongyeong, South Korea.
In this fishing region, one can observe large heaps of oyster shells in various states of decay. Shellon aims to reduce this waste by turning the substance into a new product, while also increasing public awareness of the problem itself. Furthermore, it provides a fun educational experience for children.
The main material of Shellon is calcium sulfide, which is a phosphor made with calcium carbonate from oyster shells, plus sulfur and a minute amount of metal (e.g., Cu, Mn). The phosphorescent pigment is mixed with paraffin wax and drops of essential oil. The color of the glow will depend upon which metal were used as dopants during the creation process. After absorbing UV light from the Sun, Shellon and drawings made from it will glow in the dark.
Shellon’s packaging informs users about the oyster shell waste problem, and the core idea of using waste as a resource is emphasized through a phosphorescent logo. The project shows the wide-ranging impact that a photoluminescent smart material could have on one of the significant challenges of our time: managing waste and pollutants. Further investigations would be needed regarding safety and toxicity, although some glow-in-the-dark crayons are already available and approved for use.