Researchers at Caltech looked to nature for inspiration to design more effective, longer-lasting eye implants.
Hyuck Choo, assistant professor of electrical engineering in the Division of Engineering and Applied Science at Caltech, has been working on designing an implant that measures intra-optical pressure in glaucoma patients.
The tiny implant flexes as eye pressure changes, and this change can be measured using a handheld reader. The problem he ran into was that to get accurate measurements the reader must be held at exactly a 90 degree angle with respect to the implant.
The Glasswing Butterfly’s wings are coated in tiny pillars, about 150 nanometers apart and 100 nanometers in diameter. These pillars redirect light from any angle, greatly reducing reflections, a phenomenon known as “angle-independent antireflection.”
By creating a nanostructured coating in mimicry of the butterfly’s wings, the light from the reader will pass through the implant and give the correct reading independent of the angle.
“The nanostructures unlock the potential of this implant, making it practical for glaucoma patients to test their own eye pressure every day,” Choo says.
As an additional bonus, the nanostructures discourage fouling of the implant by trapping a layer of water around it. According to Vinayak Narasimhan, a graduate student at Caltech working on the project, “Cells attach to an implant by binding with proteins that are adhered to the implant’s surface. The water, however, prevents those proteins from establishing a strong connection on this surface.”
The results of this project were published in the April 30 edition of Nature Nanotechnology.
