Weaving with light
By weaving tiny crystals into fabrics, a new technology is lighting up the night for people who lack electricity.
In the rugged Sierra Madre mountain range of west central Mexico, the native Huichol people live much the way their ancestors did—without electricity. That’s because it’s too expensive to string power lines to the remote mountain areas where they live. The lack of electricity has a direct effect on the Huichol economy.
To help support themselves, the Huichol create beautiful artwork, including paintings made from yarn and sculptures made from beads. They sell their art in cities hundreds of miles away from their villages. Often, they travel long distances by foot. And without electricity—at home or on the road, they can only work during daylight hours.
Portable lights are bringing much-needed light to the Huichol people, who live in the beautiful and rugged Sierra Madre of Mexico.Huichol art is full of symbols and meaning. This traditional yarn painting (above) was made by Huichol artist Rojelio Beuites.
When it gets dark, they must stop whatever they’re doing, explains Huichol community leader Miquel Carillo. The sales of their artwork are essential to this economy, where farming is difficult and crops often fail.
“We can only work during the day,” Carillo tells a group of researchers as night approached. “Because now, as you see, we can’t see anything, and it’s still so early. Nobody can do anything. We just wait for the sun to come up again.”
Now, a team of scientists, designers, and architects is using new technologies to provide the Huichol with light after the sun sets—no plugs necessary. The scientists’ technique involves weaving tiny electronic crystals into fabrics that can be made into clothes, bags, or other items.
A Huichol woman weaves new, light-producing technology into a traditional cloth bag.
|Kennedy & Violich Architecture, Ltd.|
By collecting the sun’s energy during the day, these lightweight textiles provide bright white light at night. Their inventors have named the textiles “Portable Lights.”
Portable Lights have the potential to transform the lives of people without electricity around the world, says project leader Sheila Kennedy, head of Kennedy & Violich Architecture, Ltd., in Boston, Mass.
“Our invention,” Kennedy says, “came from seeing how we could transform technology we saw everyday in the United States and move it into new markets for people who didn’t have a lot of money.”
As part of the Portable Light Project, Kennedy and colleagues have already donated light-producing textiles to two Huichol communities. They are working now with a group of wandering, or semi-nomadic, people in Australia. Eventually, they hope to deliver Portable Lights to similar groups around the world.
See the light
At the core of Portable Light technology are devices called high-brightness light-emitting diodes, or HB LEDs. These tiny lights appear in digital clocks, televisions, streetlights, and the blinking red lights on some sneakers.
LEDs are completely different from the light bulbs that you screw into lamps at home. Most of those glass bulbs belong to a type called incandescent lights. Inside, electricity heats a metal coil to about 4,000 degrees Fahrenheit, or 2,200 degrees Celsius. At that scorching temperature, bulbs give off light we can see.
In an incandescent light bulb, like the one above, electricity heats a metal coil until it becomes extremely hot and gives off light.
Ninety percent of energy produced by incandescent lights, however, is heat–and invisible. With all that wasted energy, bulbs burn out quickly. They are also bulky, can get hot, and are easily broken.
LEDs, on the other hand, are like tiny pieces of rock made up of molecules that are arranged in a crystal structure. When an electric current passes through an LED, the crystal structure vibrates and produces light.
Unlike incandescent bulbs, they can produce light of various colors. Within an LED, the type of molecules and their particular arrangement determines what color is produced.
For example, green LEDs make up the blinking, hand-shaped signals that tell pedestrians when it’s safe to cross a street. LEDs in a remote control, on the other hand, give off invisible infrared light that tells a television to change channels.
Light-emitting diodes come in a variety of sizes and colors. What they all share in common is their tiny size compared to incandescent bulbs. The purple-colored LED in the lineup above emits infrared light.
LEDs are tiny and extremely lightweight. There are no breakable glass parts. While the technology is still somewhat expensive, researchers are increasingly looking to LEDs for a wide variety of applications, including Portable Lights.
“A lot of people see LEDs as being the future of lighting,” says Casey Smith, a technologist in Bozeman, Mont., and a member of the Portable Light team. He developed much of the technology that make Portable Lights work.
The Portable Light team found a way to weave two LEDs into a plastic-coated textile. When turned on, these LEDs can make the entire piece of fabric glow.
Their next challenge was to figure out how to power the LEDs without electricity. The researchers knew that they wanted to tap the sun’s energy, but they couldn’t use standard solar panels such as those found on rooftops. These bulky glass panels would be too big and heavy for the Huichol to carry as they traveled through the mountains.
Instead, the researchers used a new type of solar panel, which is flat and flexible, like a placemat. Just 10 inches long and 5 inches wide, these panels can be easily sewn onto a piece of fabric.
A Mexican boy who lives in the Sierra Madre carries a woven bag, complete with LED’s and a solar panel.
|Kennedy & Violich Architecture, Ltd.|
Circuits connect the solar panel to a lithium ion battery—the type of battery found in laptops and cellular phones. And the battery, in turn, is connected to the two LEDs in the fabric. A tough layer of plastic protects the circuitry.
With just 3 hours of exposure to sunlight, the battery accumulates enough charge to power a portable light for 10 hours, Kennedy says. A membrane switch, like the soft buttons on a microwave oven, allows a user to turn the lights on or off.
Portable light technology provides enough light for this Huichol girl to do her homework at night, even though there is no electricity in her village.
|Kennedy & Violich Architecture, Ltd.|
A Portable Light weighs less than a pound and can withstand abuse because textiles are strong for their weight. Kennedy has dropped Portable Light units from as high as 30 feet off the ground without damaging them.
“With no heavy parts to break, they just float down,” she says.
Lighting the way
The Huichol have quickly accepted Portable Light technology by incorporating it into their cultural traditions.
Huichol women have long woven colorful bags on a handmade device called a backstrap loom. They use these bags to tote their belongings because their traditional clothing does not have pockets.
Each bag contains intricate patterns and symbols that reflect cultural stories and family identities. Bags and patterns are passed from generation to generation.
“It is more than just a bag,” Kennedy says. “It is vital to their life.”
Portable lights are bringing much-needed light to the Huichol people, who live in the beautiful and rugged Sierra Madre of Mexico.
The Huichol are now weaving Portable Lights into new patterns in their bags, Kennedy says. And the researchers on the Portable Light team can’t keep up with demand. More than 40 women have put their names on a waiting list.
On the other side of the world, in the Central Australian desert, Kennedy and colleagues are working to bring Portable Lights to the Arrernte people, who travel across large stretches of desert without electricity.
One goal is to use the technology to power cell phones that teachers in local schools can use to download lesson plans. That way, Kennedy says, kids won’t have to travel to cities to get an education.
It may be hard to imagine life without access to lights at night. As the Portable Light project expands, researchers hope that fewer and fewer people will have that problem.