Kelly Lin: Designing Human Powered Device for Mali Farmers

Kelly Lin: Designing Human Powered Device for Mali Farmers

(courtesy of E4C)

Kelly Lin, USCB Sorghum Press Team Kelly Lin, right, stands with the USCSB sorghum press team

Sorghum is a hardy, drought-resistant cereal crop that, when pressed and boiled, makes sweet syrup that is nutritious and sought-after in countries such as Mali. Pressing sorghum, though, is difficult. To help, Kelly Lin and a team of fellow students at the University of California, Santa Barbara (UCSB), are developing a press. The prototype of their human-powered device crushes the crop between rollers cranked with a long 4in by 4in board. Lin posted the device as an E4C workspace and invites interaction.

Lin is an active member of UCSB's Engineers Without Borders-USA chapter and he's also teaching himself Japanese, "partly because they have cool robots," he says. For his work to solve problems on farms in Mali, and for his love of Japanese robotics, Engineers for Change featured Kelly Lin as their Member of the Month (March 2012).

E4C: Can you tell us more about the press?

KL: The mission of the EWB-UCSB Sorghum Press Team is to improve the nutrition and incomes of farmers in Dissan, Mali and similar communities with a human-powered, low-cost and locally-manufactured design. The press needs to be human powered since it is the most reliable source of energy in the Dissan community. It needs to be inexpensive, reliable, and manufacturable in Mali so that it can be economically sustainable and doesn't rely on financial aid from outside organizations.

E4C: How does it work?

KL: There is a lever arm which the user pushes in a circle. The lever arm drives gears that which drives two rollers. Another user feeds the sorghum stock in between the rollers. Then the roller squeezes the juice out of the sorghum and the juice drops down into a bucket. Checkout out the UCSB Sorghum Press on YouTube

E4C: What have been the results of prototype tests so far?

KL: We have spent six months designing and building a prototype with three gears made in Mali. We were able to achieve a through-put rate of 10 inches of sugarcane stock per second. We used sugar cane for the test because sweet sorghum is not in season and sugar cane is stronger than sorghum.

E4C: What do you have left to do?

KL: In terms of the scope of my project, we need to improve the design by making the rollers adjustable, optimize the rollers to be the right size, lower the cost by simplifying the design, do  fatigue test, and make manufacturing and operation illustrations. After we are done, people will have free access to our design as well as all of our prototyping, testing, modeling, and analysis information.

E4C: So, how did you hear about E4C?

KL: I heard about E4C through a TED talk on

Thank you for all your recognition. However, the sorghum press project is a team project and would not have come this far without my excellent teammates: Hunter, Erika, Adam, and Marcela, who have worked just as hard if not harder than I have. I would also like to thank the following people: Prof. Laguette for running the UCSB ME senior projects; Advisor Mr. Bothman for starting this project and for advising us on technical issues; and Prof. Lacy for advising us on everything relating to Mali and for taking our gear design to Mali and having it made by the local machinist.


E4C is a dynamic and growing community of engineers, technologists, social scientists, NGOs, local governments and community advocates whose mission is to improve quality of life in communities around the world by facilitating the development of affordable, locally appropriate and sustainable solutions to the most pressing humanitarian challenges.

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