Her infectious laughter fills the lab as she shows off an oversized, prop bright yellow earplug.
All joking aside, the 3M senior research engineer takes her job very seriously. She’s charged with looking at ways to customize the structure-property relationships of foam systems. Essentially, she looks at the chemical formula and structure of a material and the way it interacts to give different performance, for things like those bright, squishy objects that you stick into your ear to help drown out loud noises.
“There’s a lot of design that goes into these little guys,” says Cait. “Continuously getting bombarded by all these frequencies that are getting inside the little hairs in your ears – that’s how we get hearing damage. You should be wearing hearing protection.”
Cait explains that the inner ear, or cochlea, is lined with tiny hair cells that transmit electrical sound signals to the brain. Over time, exposure to loud noises causes wear and tear of those hairs, which can lead to hearing loss.
“Hearing loss is a problem we are seeing with the aging population,” she says, “whether it’s from work, daily life or when you go out dancing and it’s so loud.”
According to the World Health Organization, 360 million people worldwide have disabling hearing loss. In adults, that refers to hearing loss greater than 40 decibels in the better hearing ear. Exposure to excessive noises, or even repeated exposure to sounds greater than 85 decibels, can cause permanent hearing loss and tinnitus, or ringing in the ears. Whether it’s from the booming vibrations at a concert on a Saturday night or the grinding machinery during your work day, loud noises are present in our daily lives.
The good news is that noise-induced hearing loss is 100 percent preventable. It’s Cait’s job to look at whether those squishy buds – made of foam – have the right mechanical and acoustic properties and the right relaxation rate. She also ensures that the polymerization is correct, so you get uniformity in all of the cell structures. Comfort is key.
“In order for you to want to wear your personal protective equipment, it has to be comfortable. If a user picks up an earplug and it feels scratchy, there’s no way they’re going to be happy putting it into their ear,” she explains. “Our number one goal is worker safety, and I’m developing materials to try to address that goal.”
Her latest project is an earplug that you can easily push in without having to roll down. It’s high-attenuating, meaning that it reduces the force of sound signals, for example, to ensure that you are being protected.
Cait’s passion for solving problems began long before she stepped foot in the lab.
She and her brother were brought up in a culture of understanding the interaction of things and how they all work. Cait grew up in a small town in southern Virginia to two engineer parents. Her parents both attended the Georgia Institute of Technology, and she fondly recalls flipping through their alumni magazine, often captivated by the imagery. Later, when she was old enough to understand the science, she came across an issue with boron carbon nanotubes on the cover. Intrigued by nanotechnology, Cait began eagerly emailing a Georgia Tech professor who was doing the research. “I got really excited, and I knew I wanted to go into nanotechnology.”
As a teenager, Cait learned that she has celiac disease, so a gluten-free diet was necessary. “You couldn’t just drive 25 miles to the store and buy delicious gluten-free bread,” she says. “I had to make my own bread.”
Undeterred, she refused to settle for bread that looks like a brick and began baking and exploring the properties of different flours. Along the way, she learned that coconut flour is good for drying things out and almond flour gives you more protein.
“That’s how I realized that materials science and polymer engineering was what I wanted to do. It was making stuff, and I like making things.”
She explains that when she began baking bread, she didn’t realize she was using the same scientific principles she would one day use in her own lab. “Bread is just foam you can eat,” she says playfully.
Cait went on to get a bachelor’s degree in polymer and fiber engineering and a Ph.D. in materials science and engineering from Georgia Tech.
And today, she makes everything from fluffy chia-seed bread for sandwiches to gluten-free sticky buns.
Science plays a huge role in Cait’s work life and in what she eats, but it also inspires some of her extracurricular activities. During graduate school, she had a friend who was working with tensegrity-inspired structures. Intrigued by the concept of tension and compression, she took up aerial dance.
“In aerial dance, with every gymnastic thing you do to maintain a balance, you have to have a pull and push,” Cait explains. “It’s basically an act of physics and is more right-brained stuff to relief the left-brained stuff that I do all day at work.”