Mahangu [Pearl Millet] Thresher
Thriving in climates in which most crops fail, mahangu, or highly nutritious pearl millet, is produced on small farms in arid parts of Africa and Asia. The cereal is consumed by millions, and demand is increasing as people migrate from rural to urban areas. Women, who traditionally prepare the meals, spend up to four hours at a time threshing and separating the grains from the stem. They first pound off the grain with a mortar and pestle or beat it on the ground, then winnow out the seeds; what remains can be crushed into flour.
While in Namibia designing bike ambulances, Aaron Wieler witnessed the lack of efficient and affordable ways to thresh and clean grain, finding small stones in his oshifima porridge. He and his former Hampshire College advisor, Donna Cohn, identified a need for a low-cost threshing machine made from locally available materials. Working in consultation with others familiar with grain production and farming in sub-Saharan Africa, Cohn acquired a supply of pearl millet and began designing a human-powered millet thresher. In 2008, she brought the project to MIT’s International Design Development Summit. (IDDS is part of a larger effort at MIT that includes D-Lab, the brainchild of Amy Smith. It focuses on low-cost solutions co-created directly with impoverished communities. The summit brings together students, professors, end-users, and professionals from over twenty countries with a broad range of experience in different disciplines for a month-long intensive workshop.) The IDDS team devised a machine, made from readily available parts. Instead of pounding the stalks, the rotating spoked wheel effectively knocks off the grain without damaging it, increasing storage life, yield, income, and time.
Women in Mali are field-testing the thresher prototype. The goal is to devise a machine that can be made and repaired locally and produce clean grain faster than the traditional method and would pay for itself in the first year. IDDS team members are designing and testing multi-worker, treadle-driven, and combined threshing-winnowing machines to further improve output.Location: ghana, mali, united states