The Itinerant Engineer

A few Saturdays back, John and I took a trip to the library.  Upstairs, projected onto the wall, we noticed an aerial image of Seattle.  Overlaid on the image were moving circles followed by breadcrumb-style trails, suggesting the motion of an object was being tracked.

Being slaves to our curiosity (we are geeks, after all), John and I investigated further, and discovered the visualization was part of an interdisciplinary study by the MIT SENSEable lab to track the voyage of nothing other than…household trash.

“The study of what we could call the ‘removal chain’ is becoming as important as that of the supply chain,” the lab’s associate director, Assaf Biderman, explains. “Trash Track aims to make the removal chain more transparent. We hope that the project will promote behavioral change and encourage people to make more sustainable decisions about what they consume and how it affects the world around them.” – MIT SENSEable Associate Director Assaf Biderman, via MITnews

To better understand the removal chain, the team affixed purpose-built printed-circuit boards, complete with cellular modems, to trash at various points around the city.  The project goal: gather as much information as possible about the path of trash, as it moves from curbside to its final destination.

They needed volunteers for the next experiment.

At home Monday night, I got a phone call.  Speaking in heavily-accented English, the caller informed me that, “We’re from MIT, and we’re here to tag your trash”.

A moment later, David Lee and Dietmar Offenhuber entered my apartment, David carrying two jugs of liquid, Dietmar with gym bag.  (“These guys are scientists“, I thought to myself.)  We dumped my trash onto the counter, next to a bag of the cellular tags, complete with handwritten hexadecimal identifiers.  David began sorting through the trash, while Dietmar took pictures using the iPhone, making sure to show the item, and the hex ID of the cellular modem.  Despite its low-quality photos and lack of flash, the iPhone’s geotagging marked where the pictures were taken — an important feature, I learned, because the cellular modems were active over the entire trip, even before they were attached to the pieces of trash.

Next, we affixed the tags to the trash; to spare my apartment from fumigation, we decided to go outside, into the alley.  David started mixing the epoxy, and soon after, we’d placed tags on a mixture of recyclable and disposable items: a piece of wood, a ceramic plate and cup, a light fixture, an aluminum can, and a plastic food container, among others.  We finished the work around 9pm, at which time I was instructed to let the epoxy set for about an hour, and then dispose of the items as I normally would.  The two had a flight to catch around 11pm, so they hurried off.

I’m really curious to see what they find; their results will be posted on the project’s homepage at MIT.

On Tuesday night, the Seattle section of the Institute for Electrical and Electronics Engineers (IEEE) held its 125 anniversary dinner at Salty’s.  In addition to meeting plenty of interesting people, I had the pleasure of hearing Dr. Henry Louie present “Engineering a Difference: Seattle University Service Work in Rural Zambia”.

The talk began with a discussion of how Zambians get water.  The lack of a reliable water grid in many parts of Zambia forces households to obtain water directly from a freshwater source. Unfortunately, predatory animals often live near water sources; each year, several unfortunate Zambians lose their lives from attacks by hippos and alligators.

In addition to water, getting electricity in Zambia is also a real challenge. Even without electricity, mobile phones are quite popular, but charging them is very difficult.  Absent reliable electricity, some Zambians walk ten miles or more to the nearest source of electricity, just to charge their phones.

In conjunction with the Seattle University Chapter of Engineers Without Borders, Dr. Louie worked to develop solutions to Zambia’s water and electricity distribution problems.  Whereas many engineers in developed countries worry about efficiency and cost, the EWB team’s solution had to be (1) constructed using readily-available materials (wood, salvage wire, etc.), and (2) serviceable by non-engineers using only hand tools.

To deliver water to the village, the team used a spiral pump-based design, made from a coil of rubber hose.  As for the electricity, the team produced a hand-crank generator capable of delivering a few watts when turned by hand.  Although charging a phone battery with the generator might take 15 minutes of more of cranking, it’s still vastly superior to walking many miles for a single charge. 

Neither of these inventions will serve an entire city, but it’s incredible what a little bit of engineering talent, applied in the right ways, can do to enrich the lives of the less fortunate.  More details are available on Dr. Louie’s Website.