Researchers at the California Institute of Technology put their heads together to combine new discoveries about the wings of a longtail glasswing butterfly with an intraocular pressure (IOP) measurement device also under development in a fellow lab. The result was a threefold increase in the device’s accuracy, according to a recent study published in Nature Nanotechnology.^1,2

Investigators first realized the butterfly’s wings were transparent because of tiny, evenly spaced pillars that “redirect the light that strikes the wings so that the rays pass through regardless of the original angle at which they hit the wings”—dubbed “angle-independent antireflection.”² 

A fellow researcher soon realized such a property might be the solution he was looking for in his ocular implant designed to improve IOP monitoring in glaucoma patients. His device, once implanted, provided accurate IOP measures using a handheld reader, but only if the reader was held exactly perpendicular to implant.²

Together, the two labs integrated pillars of silicon nitride that mimicked those of the butterfly’s wings onto the implant. Doing so yielded a threefold reduction in errors, according to the researchers.²

"The nanostructures unlock the potential of this implant, making it practical for glaucoma patients to test their own eye pressure every day," said Hyuck Choo, PhD, one of the study authors.²

Because the new silicon nitride structures also have a long-lasting, nontoxic anti-biofouling property, the researchers plan to explore other medical implants that could benefit from them.²