Trio hopes solar-powered grain thresher will reduce food insecurity in Africa

  • Susan Hanna of Shutesbury, right, displays processed pearl millet seeds winnowed Sept. 27, 2017 with a solar-powered thresher designed and built by herself, Richard “Roo” Trimble of Shutesbury, left, and Donna Cohn, professor of applied design at Hampshire College, center. Gazette Photo/Sarah Crosby

  • Richard “Roo” Trimble of Shutesbury, right, works to winnow a pearl millet panicle using a solar-powered thresher he helped design and build. Gazette Photo/Sarah Crosby

  • Donna Cohn, professor of applied design at Hampshire College, left, Richard “Roo” Trimble, and Susan Hanna, both of Shutesbury, work Sept. 27, 2017 on a solar-powered thresher they designed and built to winnow grains. Gazette Photo/Sarah Crosby

For The Recorder
Published: 9/29/2017 9:51:20 PM

SHUTESBURY — Like any inventors, Richard “Roo” Trimble, Susan Hanna and Donna Cohn are often tinkering with things. This afternoon was no exception.

Hanna and Cohn looked on as Trimble, screwdriver in hand, peered into the device for which the three collaborators have high expectations: one they hope will reduce food insecurity halfway across the world.

On this particular day, like many before, small but meaningful changes were being made to the machine.

“I noticed this little piece inside of there, the screw came loose. That’s why it’s making all that noise,” Trimble explained. To the casual observer, that noise would seem fairly quiet, but to this team of designers it’s vital that there’s minimal buzz, so that farmers can have conversations over the hum.

The machine is the latest iteration of a thresher that the three are hoping will make life easier for women farmers growing pearl millet, the staple grain in the Sahel, the semi-arid region between the Sahara Desert to the north and the Sudanian Savanna to the south.

“We created something that probably two-thirds of the people we talk to don’t know the definition of the word for,” Trimble said, laughing.

Threshing is the loosening of grain from a plant. It is the process that precedes winnowing, which separates the grain from the chaff. In this mechanical thresher, however, the grain emerges completely clean from the beginning, eliminating the need to winnow afterward.

After previous prototypes that were hand-cranked or bicycle-operated, this model is completely solar-powered. The idea won the attention of National Geographic, which together with the company GSK Consumer Healthcare recently awarded the project $25,000 as part of an initiative to reward “everyday people ” who have proposed solutions to pressing world issues.

The machine looks like a small engine placed on top of a plastic bowl, with a wooden box below all that. A pearl millet plant is fed into the motor on top, and pushed through like a pencil into an electric sharpener. A stripped stalk comes out the other end, the chaff ends up in the bowl and the clean grain is collected in the box below.

The project is a decade in the making after Cohn, assistant professor of applied design at Hampshire College, began thinking about a more efficient way to thresh pearl millet in 2007. That’s when a student, after spending time in Namibia, told Cohn about threshing practices there.

“People would tell him not to close his teeth all the way when he ate the porridge there,” Cohn said. Pearl millet there was threshed on the ground, and would often have pebbles in it after the process.

Traditional practices for threshing and separating edible grains from pearl millet plants vary widely by region and peoples, but the constant is that it can be a very labor-intensive process. The idea for Cohn was to change that.

So Cohn worked with Hampshire students and colleagues to grow pearl millet on campus, and began working on designs as part of her classes. In 2008, she posed the problem of improving pearl-millet threshing at the International Development Design Summit at the Massachusetts Institute of Technology, and conducted field tests in Ghana and Mali the year after.

“People really liked the idea of the thresher, but this one was not fast enough and not reliable enough,” she said of that early design.

So Cohn continued to gather feedback, and in 2013 came a big break: the Bill and Melinda Gates Foundation awarded the project a $100,000 grant for projects benefiting farmers in sub-Saharan Africa. That money allowed her to teach a semester-long class on the problem, to bring in other designers and to develop a prototype promising enough for field testing.

One of the designers who joined in was Trimble, a Rhode Island School of Design graduate who has designed everything from mountain bike suspension frames to fancy medicine cabinets.

“I would say for my purposes, many of the projects we do are high-end custom projects for rich clients in New York or something,” he said. The thresher was something different, however.

“This project is all about people,” Hanna added, who also joined Cohn in teaching the pearl millet class. She and Trimble, who are married, have been collaborating on projects for years. “It is also a lot about researching and understanding the culture, and understanding the cultural differences.”

Those cultural divides have been a challenge, for sure. When Cohn went to Niger to test a bicycle-operated thresher in 2014, she discovered women — who are responsible for threshing — don’t ride bikes in the villages she visited. Also, the pearl millet there was longer due to strain from drought, making it different from the pearl millet the team used back in the Pioneer Valley. Cohn had also brought a hand-cranked prototype, and the women said it wasn’t fast enough. Trimble and Hanna visited villages in Niger in 2015, and again their prototype wasn’t as fast or clean as they’d like it to be.

“It has been a constant up and down of ideas,” Cohn said. But, she said, all of that fine-tuning is a labor of love.

The team has been working with local partners, including with the National Institute of Agricultural Research of Niger, to continue testing new ideas, including further tests later this year with the latest solar-powered model.

“We also plan on working with people in the area to do most of the production, as much of the production as possible,” Hanna said, mentioning local artisan foundries that cast aluminum in Niger as likely partners. “Part of this trip is about researching that whole aspect, how it could be made and who it could be made with.”

“We want to be really sure we have an iron-clad product before we go into bigger production,” Trimble added.

The next step in the process, after a design is finalized, is to build 50 threshers and distribute them for feedback, the group said. Getting input from farmers using the threshers for an entire growing season, they said, will be the true test of their concept and whether it works in the field. From there, they hope to scale up the manufacturing and begin selling subsidized versions of the machine.

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