Although I have never met her, Amy Smith is fast becoming one of my favorite “cool” people. Amy is that instructor at MIT that was awarded a McArthur fellowship last year for her innovative inventions, one of which is the screenless hammermill. Now, I learn that Amy is a driving force behind MIT’s progressive D-Lab. Okay, let me take a moment and explain this a bit.
D-Lab is a year-long series of university courses and field trips at the prestigious Massachusetts Institute of Technology, located in Cambridge, Massachusetts (which is right next to Boston). The program is divided into two parts that coincide with the typical “Fall” and “Spring” semester schedules of many, if not most, U.S. universities. During the fall, students are given a basic background in international development and appropriate technology. This is done through guest speakers, case studies and hands-on exercises. Then in the spring, they have the opportunity to travel to Haiti, India, Brazil, Honduras, Zambia, Samoa, or Lesotho and continue their work in a design class in what is called an IAP fieldtrip (I had to go to Google to learn that “IAP stands for “Independent Activities Period” at MIT). During the fall class, the students will have partnered with community organizations in these countries they plan to visit and they develop plans for the IAP site visit. As a part of preparing their fieldtrips, students will learn about the culture, language, economics, politics and history of their host countries.
This D-Lab sounds pretty cool already, but the real “kicker” in all this is the really cool stuff that these student engineers and their mentors come up with.
I’ve already mentioned the Screenless Hammermill, and I will mention it again briefly, but you can read more about it at Screenless Hammermill
In addition to the mill they have created a
Solar Water Disinfection Process , a Low-Cost Water Testing Process , a Phase-Change Incubator and a process for making Charcoal From Sugarcane .
Also, in looking around D-Labs Home Page I see a link titled “Down and Dirty Tech Trick Of The Day: How to fix a community water system using toilet technology.”I go to the site and in fairly plain language (I say “fairly plain” because even I could understand it.) the web page sets out a problem for a community in a developing nation and how it was solved. The problem was that a water purifier system using chlorination kept having pressure fluctuations that caused inconsistencies in the effectiveness of water treatment.
The web page goes on to describe the system that is basically made of two holding tanks, one holding water piped down from a spring in the mountains and the other filled with a chlorine solution and is set to drip into the tank filled with the spring water. The drip rate of the chlorine is calculated upon what the flow-rate of the water. But the valve used to control the drip rate of the chlorine allows the flow of chlorine solution to slows down to about half the original rate with a few minutes. In trying to allow for this ineffective valve sometimes the chlorine levels were too high, sometimes too low, but almost always, the water was unsafe to drink.The D-Lab team in Honduras learned of the problem in January, 2004 and took an idea from the construction of the toilet.
The Team constructed a solution to the problem using a red plastic gas container for a reservoir, the clamp from an intra-venous drip kit as a flow controller and the valve apparatus found in almost all flush toilets in order to control the level of liquid in the reservoir.
The web page states: “Through this simple feedback mechanism, the level of chlorine solution is kept roughly constant in the small red container. This means that the pressure at the IV clamp is also kept roughly constant. Which, most importantly of all, means that the chlorine is added to the water at a constant rate, meaning that safe chlorination is made possible.
“The team went to the local pharmacy and the hardware store to get the parts, and for just a few dollars they had everything they needed. With the help of the plumber, who had several suggestions for improving the system, they installed it in the tank.
“After the apparatus had been in place and functioning for three days, the team tested the treated water for chlorine levels and the presence of bacteria. All tests indicated that the water was clean and safe! Additionally, the retrofit has also enabled the system to run for three days at a time without requiring any adjustments by the technician.
“Perhaps most importantly of all, however, this fix used locally available materials and locally available skills. A fact that will enable this technology to be a sustainable solution for the community in which it was developed, allowing for local innovation in the near future.
“One year later, the team returned to Honduras and found that not only was the chlorine dispensing system still working, but that the plumber had devised several improvements to the system and had installed them in other water tanks in the surrounding area”.
I will leave you to read the specific details of how the simple parts of this system interact to provide and inexpensive solution to a serious health threat in a community in a developing country.
The page is currently a javascript program imbedded in the Home page, so I can’t post the URL here. So, just go to the Home Page: and click on the “Down and Dirty Tech Trick Of The Day” link. If the vignette about the water system in Honduras is not there, I’m sure that there will be something just as fascinating.
There is also an interesting news story from the Boston Globe that is posted on the D-Lab “ News ” web page. “Shared beliefs engineer technical changes for better Pair join forces to aid Haitians”
This story details how D-Lab, Amy Smith and an activist in the Boston Haitian community partnered to deliver technological support to communities in Haiti in the form of a synthetic charcoal created at D-Lab, as well techniques for a water purification and a drip irrigation system and some solar cell technology.
The synthetic charcoal is made out of fibrous sugarcane remains. This is important because 98 percent of Haiti is deforested and the vast majority of homes still use wood to cook. And of course, the continued use of wood would further exacerbate the deforestation, which precipitates other disaster consequences. Besides saving trees, the sugarcane briquette are also smokeless and much less likely to cause respiratory illnesses.
Sticking to my promise to keep these articles short, I have to stop here, but hopefully before too long I can post another article about D-Lab and the great and wonderful things they are doing to improve the world. But before I go, I gotta do this. In her course presentation, Amy Smith does a very good job of explaining the differences between Indigenous Technology, Industrial Technology and Intermediate Technology. And I hope she will forgive me for quoting so liberally from her class notes when I post the three examples which illustrate the differences between these technologies. Those three examples are in the areas of Grain Milling, Brick Pressing and Water Collection.
“Grain Milling
With the indigenous grain processing techniques found in many African cultures, women may spend many hours every day pounding grains by hand. The industrial solution is a conventional commercial grain mill, which can grind this much grain in a few seconds. But costing thousands of dollars, it’s simply too expensive to be available for the vast majority of people.
"The intermediate technology solution for grain milling is a small mill operated by a local entrepreneur or coop – for instance, Amy Smith’s hammer mill shown in the slide. It’s affordable for the village-level entrepreneur, whose investment can be spread across many users. And it’s nearly as fast as the industrial solution, grinding a day’s worth of grain in a couple of minutes.
"Brick Making
Because of its large scale, the industrial brick-making operation only makes sense in urban areas. If all brick making goes to the cities, it pulls jobs and resources away from the rural population. An intermediate technology solution is a “hand press.” It is more efficient than indigenous brick making completely by hand, but operates on a scale that can still be deployed locally.
"Water Collection
In many regions, the indigenous solution for water collection requires women to carry jugs of water many hundreds of meters to several kilometers. Obviously the time and effort required is a drain on other things they might be doing. The industrial solution for water collection is classic “big development.” Dams and associated infrastructure cost many millions of dollars, and operate on a scale that may create other environmental or social issues. This treadle pump is an example of an intermediate technology – low cost, small scale, and very useful. It was designed and constructed by an NGO. It allows one person to collect enough water in a couple hours work to irrigate fields for several days.”
I really have to go now, but the next time I write about these guys, at D-Lab, I want to tell you about how they distinguish “Appropriate Technology” from “Intermediate Technology.”
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