Subscribe to Newsletter
Business & Profession Business and Innovation

Sweet Tears

Many people with diabetes would be happy to see the back of their blood glucose monitor and daily finger-prick tests. Enter: a team of scientists from the Ulsan National Institute of Science and Technology (UNIST), South Korea, who have created a means of wirelessly monitoring glucose levels with a soft contact lens.

“Embedded within our smart contact lens are electronic circuits, an antenna, a glucose sensor and LED pixels integrated as stretchable forms,” explains Jang-Ung Park (1). “This improves the comfort and wearing-time of the lens compared with previous smart lenses that were hard due to having brittle and more rigid components.”

Their sensor comprises a graphene surface to which glucose oxidase (GOD) enzyme is immobilized. Tears (containing glucose) pass through the sensor channel; GOD oxidizes the glucose, which releases electrons in a concentration-dependent manner, which the sensor detects, enabling the glucose concentration to be determined (1). The sensor contains an LED that responds to the changes in resistance (which is coupled to tear glucose concentration). Below 0.9 mM, the LED emits light; above this, the LED pixel is turned off, providing a visible cue that the glucose threshold has been reached (Figure 1).

Figure 1. The soft, smart contact lens is comprised of a hybrid substrate, functional devices (rectifier, LED and glucose sensor) and a transparent, stretchable conductor (for antenna and interconnects). Electric power is wirelessly transmitted to the lens through the antenna, and activates the LED pixel and the glucose sensor. If glucose levels in tear fluid above the predefined threshold level (0.9 mM), the pixel turns off (1).

So far, the team has demonstrated that the device can respond to changing glucose concentrations in rabbit eyes, and they plan to move into clinical tests in humans. But what of its applications for ophthalmology? The team write that their novel system could “provide a platform for wireless, continuous, and noninvasive monitoring of physiological conditions, as well as the detection of biomarkers associated with ocular and other diseases,” – and drug delivery isn’t out of the question.

Receive content, products, events as well as relevant industry updates from The Ophthalmologist and its sponsors.

When you click “Subscribe” we will email you a link, which you must click to verify the email address above and activate your subscription. If you do not receive this email, please contact us at [email protected].
If you wish to unsubscribe, you can update your preferences at any point.

  1. J Park et al., “Soft, smart contact lenses with integrations of wireless circuits, glucose sensors, and displays”, Science Advances, 4, aap9841 (2018).
About the Author
Ruth Steer
Related Product Profile
Uncover the Unique DNA of SPECTRALIS®

| Contributed by Heidelberg Engineering

Product Profiles

Access our product directory to see the latest products and services from our industry partners

Here
Most Popular
Register to The Ophthalmologist

Register to access our FREE online portfolio, request the magazine in print and manage your preferences.

You will benefit from:
  • Unlimited access to ALL articles
  • News, interviews & opinions from leading industry experts
  • Receive print (and PDF) copies of The Ophthalmologist magazine

Register

Disclaimer

The Ophthalmologist website is intended solely for the eyes of healthcare professionals. Please confirm below: