New contact lens technology to help diagnose and monitor glaucoma and other ocular health conditions may soon be ready for clinical trials. A team of researchers from Purdue University worked with biomedical, mechanical and chemical engineers, along with clinicians, to develop the novel technology. The team enabled commercial soft contact lenses to be a bioinstrumentation tool for unobtrusive monitoring of clinically important information associated with underlying eye health conditions.

Biomedical engineer Chi Hwan Lee developed a sensor that can be placed on an over-the-counter contact lens and is used to detect glaucoma in patients. Photo courtesy of Purdue University/Rebecca McElhoe
“This technology will be greatly beneficial to the painless diagnosis or early detection of many ocular diseases including glaucoma,” said Chi Hwan Lee, Purdue’s Leslie A. Geddes assistant professor of biomedical engineering and assistant professor of mechanical engineering, who is leading the development team. “Since the first conceptual invention by Leonardo da Vinci, there has been a great desire to utilize contact lenses for eye-wearable biomedical platforms.”

The team’s work is published in Nature Communications. The Purdue Research Foundation Office of Technology Commercialization helped secure a patent for the technology, which is available for licensing.

Purdue biomedical engineer Chi Hwan Lee specializes in sticktronics and custom-printed soft medical sensors. Photo courtesy of Purdue University/Rebecca McElhoe
Sensors or other electronics previously couldn’t be used for commercial soft contact lenses because the fabrication technology required a rigid, planar surface incompatible with the soft, curved shape of a contact lens. The team has paved a unique way that enables the seamless integration of ultrathin, stretchable biosensors with commercial soft contact lenses via wet adhesive bonding. The biosensors embedded on the soft contact lenses record electrophysiological retinal activity from the corneal surface of human eyes, without the need of topical anesthesia that has been required in current clinical settings for pain management and safety.

“This technology will allow doctors and scientists to better understand spontaneous retinal activity with significantly improved accuracy, reliability and user comfort,” said Pete Kollbaum, director of the Borish Center for Ophthalmic Research and an associate professor of optometry at Indiana University, who is leading clinical trials.

During his research, Lee learned that there are not many ways to effectively test and measure pressure on a person’s eyes, even during sleeping. Thanks to his persistence, collaboration and innovation, his lab group began taking standard over-the-counter contacts and placing sensors on the lenses.

Examples of sticktronics technology used for custom-printed soft medical sensors. Photo courtesy of Purdue University/Rebecca McElhoe

Patients can wear the specialized contacts throughout the night, and pressure measurements are sent to a telemedicine monitor, where physicians can learn more about glaucoma. Currently, a handful of patients in Indiana are trialing this technology. Further collaboration on this project included Bryan Boudouris, a professor of chemical engineering at Purdue, who helped develop the wet adhesive for attaching the sensor to the contact lens.

Lee’s lab recently received a $2 million grant from the National Institutes of Health with Yannis Paulus, an assistant professor of ophthalmology at the University of Michigan Ann Arbor, who helped evaluate the contact lens device in a drug delivery setting.

Lee’s contact lens research grew out of his work with a platform technology called sticktronics, which are sticker-like items that contain electronics or smart technology. Sticktronics offer the ability to physically separate materials in existing items and turn an item into a sticker that can be more flexible or transparent, especially on curved displays and biomedical sensors. “You can change the form factor from rigid and stiff to flexible and stretchable,” Lee said.

Chi Hwan Lee and his students have developed an electronic glove that simulates the sense of touch for prosthetic hands. Photo courtesy of Purdue University/Rebecca McElhoe
Lee’s lab space includes 3D printers so students can make parts for an electronic glove, which simulates the sense of touch for prosthetic hands. The technology is being tested at a physical rehabilitation center in Chicago—you can watch the video below. The lab also has standard sewing machines that can turn strands of specialized nanotechnology textiles into clothing.