'Lightest Light' LEDs to Transform Brain Science, Digital Displays, Say Studies

The research moved forward under the leadership of the University of St. Andrews' school of physics and astronomy.

On a long enough timeline, the new LEDs could also see use in future treatments for various neurological diseases — where light-gated proteins may deploy to selectively modulate patients' brain activity.

LEDs' stability under high humidity, water makes them ideal for wearables

Previous attempts to create ultra-thin organic LEDs saw problems with poor stability in air and moist environments. But these new LEDs showed exceptional robustness in tests — showing a capability to survive underwater for weeks, in addition to withstanding exposure to gas plasmas and solvents.

The new LEDs can also bend around a razor's edge thousands of times without losing any functionality — an easy experiment serving as a substantial testament to their excessive durability.

This noted robustness, excessive form factor, and mechanical flexibility of the new light sources open the door to several potential uses and applications beyond mobile technologies. For example, they could become integrated into work surfaces, various packaging, and clothing as self-emissive indicators without packing extra weight and volume on the product. Additionally, the LEDs' stability under high humidity and water makes them ideal for wearables — perhaps as a biomonitor in need of skin-contact, or in use with implants for biomedical research.

Scientists used light from array of miniature organic LEDs

Professor Malte Gather of St. Andrew's school of physics and lead scientist for both studies said: "Our organic LEDs are very well suited to become new tools in biomedical and neuroscience research and may well find their way into the clinic in the future."

Collaborating with Stefan Pulver of the school of psychology and neuroscience for a separate study, the scientists employed light from an array of miniature organic LEDs — making use of a neuroscience method known as optogenetics to control and direct the locomotion of fly larvae with great precision.

Scientists poised to test range of hypotheses on neural locomotion

Maneuvering light to specific body areas of crawling fly larvae helped the researchers stimulate and silence sensory neurons with reliable results. Varying when and where light was delivered, the scientists saw the larvae crawl forward or backward — effectively controlling the speed of crawling and other aspects of the creatures' movement with the dynamics of light.

"While the precise neuronal mechanism behind the animal response remains unknown, we are now in a much better position to test a range of hypotheses related to the locomotion of these organisms," said Caroline Murawski of the school of physics and astronomy, who was also first author of the second study, Phys.org reports.

Organic LEDs could help supplant lost vision, hearing, sense of touch

As of writing, the researchers are combining this latest breakthrough in creating lightweight, flexible, and robust organic LEDs with what they later learned about controlling neural activity in flies — using light sources implanted in the brains of vertebrate organisms. This will help researchers further studies of brain activity in a manner less invasive and highly-versatile than conventional methods.

While this will help advance future development of mobile displays — paving new roads for basic research — the technology from these studies may also improve clinical treatments via the invention of optical interfaces capable of sending information to the brains of people who have lost vision, hearing, or their sense of touch.