Investigating the plastic decomposing ability of Tenebrio molitor using carbon dioxide sensors

Abstract

According to a group of Stanford scientists, mealworms, the larva of darkling beetles, can digest Styrofoam, a type of polystyrene, and break it down into carbon dioxide. This paper investigates the plastic-digesting property of mealworms on different types of plastic, namely polystyrene (PS), low- density polyethylene (LDPE) and polyvinyl chloride (PVC). Since mealworms breathe in oxygen and exhale carbon dioxide. To measure the extent of plastic intake, we explored an alternative method to measure the extent of plastic digestion - using Arduino carbon dioxide sensors instead of calculating the difference in weight of plastic. As the increase in the exhalation of carbon dioxide is indicative of the amount of plastic consumed, the authors measured the change in carbon dioxide concentration of the mealworms' environment as they consume plastic. This is put into comparison with when the mealworms respire without food. The results show that mealworms consume Styrofoam to a certain extent. However, they are mostly unable to digest polyethylene and polyvinyl chloride, likely due to their elasticity and high density respectively.