Bacteria charger

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If you’re going to talk on your cell phone, you’ve got to keep the battery charged. Engineers and bugs may help. We’ll see how, today on Engineering Works!

Everybody has a cell phone these days. They’re everywhere. Some places, they’re the only phones there are. Consider Uganda. In rural Uganda fewer than one household in 100 is connected to the utility grid. No electricity. No landline telephone. But more and more people have cell phones. In developing countries, it’s cheaper and easier to build a cell network than a conventional landline system.

Of course, this brings another problem. How to recharge cell phone batteries without electricity to power the charger. This is where the engineers and the bugs come in.

Some engineering students have come up with a way to capture the energy that bacteria produce as they chow down on plant wastes to get electricity. It’s called a microbial fuel cell, or MFC. MFCs would be a perfect fit for electricity in rural areas of developing countries.

But don’t look for MFCs at your local big box store any time soon. The inventors are still early in the development process, and their prototype is kind of slow. It would take about six months to recharge a cell phone battery. But you can connect several together to get more power, and the engineers say future versions are likely to be more powerful still.

Our batteries are going flat, so we’re out of here. See you next time.

EngineeringWorks! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. Engineeringworks.tamu.edu.

Food irradiation

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Everybody does it. Nuke it! Today on Engineering Works, we’ll find out how the biggest microwave oven you ever thought of makes food and other things safer.

Microwave ovens and food just seem to go together. They’re pretty handy. A minute or so and last night’s leftover fried rice turns into a tasty lunch today.

Food engineers are using a device sort of like a microwave on steroids to rid all kinds of food of unpleasant bacteria like salmonella and E-coli that can make us sick. It’s called irradiation.

Irradiation is causing quite a stir in the world of food. Some people think it’s a great idea. In one simple process, they say, food can be made safe from contamination by bacteria. And you can store irradiated food almost forever.

Other people think it’s scary. As soon as you say irradiation, they start thinking about things that glow in the dark.

Actually, we’ve been irradiating food for a long time; more than 90 years, in fact. And no one’s been contaminated yet by irradiated food. All the food the astronauts eat while flying the space shuttle or circling the globe on the international space station has been irradiated. And you’ve been using irradiated spices and cosmetics for years.

So the next time someone mentions irradiated food think of fried rice and astronauts and dig in. You’re in good company.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. Engineeringworks.tamu.edu.

Precision agriculture

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Old McDonald’s farm was never like this. We’ll spy on how satellites and other new technology are helping farmers keep track of their cows and corn — today on Engineering Works!

McDonald never heard of the global positioning system – GPS. But if he was farming these days, he’d probably be using global positioning system technology to keep track of his cows and all the other animals. GPS satellites, computers, new sensors and other high-tech tools are helping farmers “harvest�? information from their fields – information they can use to harvest more crops.

Sensors in this cornfield, for instance, are measuring how fertile the soil is.

GPS satellites overhead read where the sensors are, and the farmer’s computer puts the data together and draws a map to show which areas need more fertilizer, and what kind.

Other sensors “see�? where pests are chowing down on tasty crops, and map out where to apply insect killers. It’s all about making farming more efficient, doing the right things at the right time.

If you know exactly how much fertilizer and pesticide you need, and where you need it, you can be sure you’re applying enough without putting down too much. The same technology can also warn you about water pollution and other environmental problems before they get out of hand.

Bet Old McDonald wishes his farm was high-tech.

EngineeringWorks! is made possible by Texas A&M Engineering and produced by KAMU-FM in College
Station. Learn more about engineering. Visit us on the World Wide Web. Engineeringworks.tamu.edu.

Programmable cells

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Computers are getting smaller all the time. Some engineers are taking this idea to extremes. We’ll check it out – today on Engineering Works!

These engineers are looking into a new field of science, or technology, called synthetic biology. The idea is to use living cells to do many of the things computers based on silicon chips do now, plus some other things – detect hazards, build structures, repair tissues and organs inside the body. It sounds like something out of a bad movie, but these guys are serious.

For instance, some electrical engineers have already programmed bacteria cells to glow red or green when they get a chemical signal from other bacteria cells. When they sense a high concentration of the signaling chemical, they glow green. When there’s less of the chemical, they glow red.

But that’s not all. One engineer has programmed cells so they make a red-and-green bull’s eye around the chemical that’s signaling them. Red close in where there’s more chemical. Green farther out, where there’s less.

The researchers are pretty excited about that bull’s eye. It could be the first step on the way to using programmed bacteria to build stuff, maybe fix things inside your body. If they can program the cells to turn colors, they think they can get them to deposit other stuff when they get the right signals.

We don’t know about our cells, but our program is just about over for this time. See you later.

EngineeringWorks! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web. Engineeringworks.tamu.edu.