Tired of waiting for her local government to find a solution for the plastic waste produced by households and factories, Nzambi Matee, a Kenyan materials engineer, invented a process and designed a machine that converts plastic waste into bricks. These bricks are denser and around five to seven times stronger than concrete. Her work has been seen as an important capital resource for Kenya’s economy, as the machine simultaneously solves the issues of plastic waste disposal and a lack of durable housing.