UCR Science Lecture Series

Yesterday I went to a talk held at UCR as part of a science lecture series open to the public. Cheryl Hayashi, a biology professor at UCR, gave a talk on biomimetic technologies – innovations that imitate nature. Hayashi advocates that there is a lot to learn from nature. Shaped by natural selection over a super-human stretch of time, designs found in nature are often superior to manmade technologies.

Hayashi’s slight frame packs a bundle of energy and enthusiasm for her work. She wears comfortable shoes and slacks and sports hair slightly more fashionable than the average professor. “Do you see this here?” she asks as she walks from one side of the room to the other, making sure that everyone in the audience can see what she is pointing out. It is a picture of sand. “There are two eyes here,” she draws her hand over the picture, “and here are the legs coming out.” The audience “oooohs” in comprehension – now we see a spider camouflaging itself in the sand. Hayashi shoots a mischievous look at us and exclaims, “You guys will believe anything, huh!” She’s just kidding, though. She assures us there really is a spider there.

Hayashi's fascination with nature is infectious as she takes us through current technologies that imitate nature. She offers the example of a butterfly that does not use pigment to color its brilliant metallic blue wings. Instead the wings are made of tiny lens-like scales that nature has optically engineered to reflect blue wavelengths of light back to us. Sonar, often used by the military, has been used for much longer by bats and dolphins to detect their surroundings. Speedo recently developed swimsuits that mimic shark skin to create more efficiency for swimmers. And the inspiration for Velcro came to an inventor when he came back from a hike to find himself and his dog covered in fast-sticking seed burrs.

Hayashi herself works with spiders and researches spider silk. She urges us to imagine what it would be like to be a small spider interacting in a giant’s world. They need their silk to interact with their surroundings. Incredibly, spiders create 7 different kinds of silk. Hayashi’s lab measures the properties of the silk and researches how spiders produce it. Spider silk can stretch to twice its length without breaking and has superior strength, extensibility, and toughness compared to manmade materials. While a string of spider silk 1mm in diameter could lift a cat (11 pounds), a 20mm diameter string could lift a hippo (4400 pounds). That’s a tough string of silk.

Some promising applications for spider silk include tough, lightweight gear such as bullet-proof vests and medical products such as bandages and sutures. Spider silk also exhibits muscle-like properties: wetness and humidity cause the silk to contract. It could provide an alternative to artificial muscle tissue, which contracts through electrical impulses. Producing spider silk in mass quantities for commercial applications presents another challenge and opens a new topic of research.

After this talk I am left impressed by designs that occur in nature. I am also curious – what does Hayashi do with spiders she finds in her house? She wouldn’t squash them, would she? Perhaps she takes them with her to lab.

For more info on the Science Lecture Series, visit here!