Meet The Engineer: Ann Mescher

As a kid, Ann loved to play outside on her family's farm, tinkering with the tools and farm equipment. Today, she still loves to have her hands on her work as a Professor of Mechanical Engineering in the Polymer Optics Laboratory at the University of Washington.

In Ann's lab, engineers and scientists use polymers—a combination of small molecules bonded together to create larger molecules with exciting new optical properties. Common objects like plastic bottles, styrofoam, and chewing gum are all made from polymer materials.

In the field of photonics research, Ann's team uses various polymer materials to create a new type of optical fiber. Instead of using solid glass to guide wavelengths of light, this fiber contains holes that can be empty or filled with polymer material. When light travels down these fibers, the researchers can manipulate the pulses of light and amplify the signals or filter out certain wavelengths. When the holes are filled with a special new polymer, it is even possible to convert invisible light to visible light.

Eventually, the engineers hope to make the air holes smaller than one micron in diameter. In comparison, a strand of human hair is about 50-100 microns thick. With holes about the size of one micron or less, it will be possible to manipulate light over a wider range of wavelengths, including visible light. Right now, Ann's team is testing the limits of how small they can make these holes.

Ann got her start as an engineer with math and science in school. She also liked to draw and paint in her free time. She still uses her school knowledge every day and is excited to study photonics as an engineer. "Mechanical devices are slow, electronics are faster, but photonics are even faster!" explains Ann.

As a suggestion for young scientists, Ann suggests, "Take all the classes that you can to really challenge yourself."

Image: An example of the polymer fiber with holes to guide signals.

Solar Technology Makes Progress Sunlight is the cheapest form of light energy—it's free! But to use sunlight, you need a way to convert its optical energy into electrical energy. We use solar cells, which supply electrical power to items like a pocket calculators or satellites. Producing solar energy can be less polluting than producing fossil fuel energy, but it is more expensive to create solar cells. Scientists with the photonics center at the Georgia Institute of Technology are studying how to create lower cost solar cells. As part of the photonics team with the University of Washington, they are using new materials to convert sunlight into electricity.Typically, solar cells are created with silicon-based materials. But Professor Bernard Kippelen and his team have developed solar cells using pentacene, a material created with carbon and hydrogen. Pentacene can be spread more thinly than silicon and could be manufactured on a flexible material at a lower cost. This means that solar cells could be used to power devices like laptop computers, portable radios, and hopefully even larger items. It will take several more years of research before we see a product in the store, but progress is moving the technology forward. Can you think of devices that you would want to unplug and power with solar cells?Image: A thin-film, flexible solar cell. Photo: MDITR