Current Technologies

CTI’s hand-cranked burr mills, or grinders, produce flour from various grains and make a creamy paste from roasted nuts. The two grinder models, Omega and Ewing, were designed specifically for families in developing countries to process crops for home consumption and to sell in the local market. Sturdy and easy to use, CTI’s grinders are built to withstand challenging environments, and unlike other burr mills on the market, they come equipped with heat treated burrs that withstand wear. Both models can grind various nuts and grains, cocoa, shea, dried breadfruit, maize, soybeans, seeds, coffee, dried beans, dried cassava, dried moringa, and many other crops.

- Informational Brochure (PDF)
- Pedal Powered Grinder (PDF)
- Pedal Powered Device Construction Guide (PDF)

Ewing IV

The Ewing grinder was optimized in 2011 and with its new streamlined, more compact design, the Ewing IV grinder will ship in a flat-rate post office box for $15 in the U.S. and under $60 around the world. The Ewing IV grinder can be operated by hand or pedal power.

In CTI’s inventive Cool Storage Shed, crops are stored in a ventilated structure over a pool of water. As the water evaporates, the air temperature cools and preserves stored crops. The increase in shelf life allows famers to sell their crops off season, adding significant value to their market price. Additionally, farmers using the storage shed have more time to process their crops into value-added products. The cool storage shed is currently used in India to store potatoes and other vegetables, allowing farmers to sell their potatoes later in the season at a 300% increase in market value.

Peeler

CTI’s peeler removes skins from potatoes so they can be sliced, cut and dried. Converting potatoes into chips or strings allows farmers and entrepreneurs to take advantage of higher prices and longer shelf life in the chip market. The peeler is hand-powered, but can be motorized. It is constructed from a barrel that is lined with an abrasive material. As it is rotated, the potatoes tumble and rub against the abrasive material until they are fully peeled.

- Potato Peeler and Slicer (PDF)

This device thinly slices large quantities of potatoes, which can then be consumed or dried and sold in the market. The slicer can be bicycle powered or motorized. Both the peeler and slicer are currently used in India as a basis for microenterprises. With the exception of the slicer blades, peelers and slicers are made by local manufacturers from parts and metal stock readily available in India.

The CTI Water Chlorinator is an inexpensive, non-electrical water disinfectant system designed for gravity supply water systems. Using chlorine tablets, which cost just pennies per day, the unit delivers a controlled dosage of chlorine to water, killing most pathogens found in rural drinking water systems. With training, the chlorinator can be built locally with PVC tubing and fittings and can be installed in a matter of hours with basic hand tools. CTI's Water Chlorinator is providing clean drinking water to nearly 90,000 people in rural Nicaragua.

- Water Chlorinator Factsheet (PDF)

Interested in obtaining a Water Chlorinator? Fill out our Water Evaluation Form (PDF) and email it to cti@compatibletechnology.org.

With this simple, yet effective corn sheller, dried corn can be removed from the cob with an easy twist. Local craftsmen can make and sell the wooden sheller at a low cost within the reach of most families. The sheller can be made with very simple tools: hand saw, coping saw, hand drill and some nails or small bolts.

- Constructing a corn sheller (PDF)

Emerging Technologies

When African farmers told CTI that they lose about a third of the grain they've harvested using rudimentary processing tools, CTI engaged scientists and engineers (from the USDA, ICRISAT, and the OneLab Initiative) to help devise a more efficient way for subsistence farmers to process their grain.

After years of development, CTI has nearly completed its design of hand-operated equipment for threshing and winnowing grain. In field tests with pearl millet and sorghum, the set of devices produced high quality grain in a matter of minutes, capturing 90% of farmers' harvest. This breakthrough technology can significantly reduce women’s workloads and increase farmers’ grain yields in some of the most famine-prone regions of the world.

- Grain Processing Tools (PDF)
- Watch Grain Processing Tools Video

CTI researchers and engineers are developing a system for processing breadfruit into a shelf-stable flour. Breadfruit is a high-carbohydrate fruit that is abundant in many tropical nations that struggle with hunger, but because it begins to rot 48 hours after harvest, it has been underutilized as a food source.

CTI engineers, in collaboration with engineering students from the University of Saint Thomas, are designing a manual processing system—a shredder, dryer, and grinder—that can be used in impoverished communities to make breadfruit flour. The system will go through rigorous tests at the Breadfruit Institute to demonstrate the equipment’s functionality and economic viability.

- Breadfruit Processing System (PDF)

Groundnut Harvester, Stripper and Sheller

In 2009, CTI and our partners (Tanzania’s Sokoine University of Agriculture and ICRISAT) were awarded a grant from the McKnight Foundation to help farming villages in Malawi and Tanzania improve groundnut (peanut) production and child nutrition. CTI is collaborating with groundnut growers in Malawi and Tanzania to develop affordable and efficient tools for harvesting, stripping, and shelling groundnuts—operations which are usually performed tediously by hand and largely by women.

- Groudnut Processing Tools (PDF)

An estimated 400,000 women in Ethiopia process peppers by hand; a laborious procedure that turns fresh peppers into higher-value products of dried flakes, seeds, and powder.

The Pepper Eater (featured in National Geographic) is a device in development that mills dried peppers with a hand-crank much faster than the traditional method of flaking peppers by hand or with a mortar and pestle. The Pepper Eater concept was developed by students at Stanford University, and it was transferred to CTI for our volunteer and staff engineers to redesign. CTI has redesigned a prototype that we believe will meet the criteria of pepper producers in Ethiopia. We have scheduled a field trial in Ethiopia to meet with pepper processing communities and co-ops for their evaluation of this new device.

- Pepper Eater (PDF)

In Bangladesh, CTI supports a facility that converts rice hulls (an inedible by-product of rice production) into low-cost fuel sticks. Women sell the fuel sticks, which are used as cooking fuel, in small retail shops at a price comparable to firewood. With help from students at Michigan Technological University, CTI is making engineering improvements to the fuel stick technology, which will allow for the expansion of the enterprise model into additional countries.

- Fuel Sticks (PDF)

CTI has developed a set of rice hulling burrs that can be attached to CTI grinders for dehulling rice. Traditionally, farmers often remove rice hulls by beating their harvest against the ground, a time-consuming and wasteful practice. CTI's prototype Rice Hulling Burrs are currently undergoing field tests by farmers in several countries in Africa and Asia.

CTI engineers are designing a water chlorination system which will use readily available salt to disinfect drinking water. The device may be operated by pedal or solar power. Initial tests on the device are being conducted with assistance from the University of Saint Thomas.