The firefly is one of the most amazing animals on Earth, mainly due to the fact that it is one of the few living creatures that possess an interesting natural feature called bioluminescence. This feature allows the tiny flying bug to be visible at night, and it is produced by combining the oxygen in the air with calcium, luciferin, adenosine triphosphate (ATP), and a bioluminescent enzyme found in the firefly’s body. However, unlike light bulbs, the energy that the firefly produces to create light is fewer, and the light would also not transform into heat. If the firefly’s light does turn into heat, the animal may not be able to survive the temperature that its body produces, hence the reason why the bioluminescent ability of the firefly is considered a “cold light” that doesn’t require a lot of energy.
Because fireflies would naturally produce light without excessive amounts of energy, many researchers and engineers have tried to copy the bioluminescence of the firefly and apply it to LED lights, as they believe that the biomimetic technology would help LED lights consume less energy, electricity, or power. Although there have been many research studies involving the bioluminescence of fireflies over the years, it was only in 2019 when a group of researchers has finally come up with a credible proposal of a LED light that copies the firefly’s abilities. To know more about this concept, let us dive into the amazing origins of firefly-inspired LED lights.
Origins of Firefly-Inspired LED
In 2019, a group of researchers at Penn State University in the United States had proposed a design concept for LED lights that mimics the firefly’s ability to produce light. In their proposal, they conceptualized a design wherein the LED bulb has similar asymmetrical micro pyramid structures that almost looks the same as the pattern that is found on the abdomen where the fireflies can create light. The researchers stated in the paper that the obtuse slopes that can be seen on the proposed LED bulb could increase its brightness by 90 percent while also decreasing its energy consumption.
According to the principal author of the paper, Chang-Jian Chen, who is also a doctoral student in electrical engineering, upon closer inspection of a firefly’s abdomen, they noticed that the microstructural patterns found on that specific body part are asymmetrical, and this asymmetry could be the reason why the bug can produce brighter lights with only utilizing low energy.
In the research paper, the authors also wrote that there are two reasons why the asymmetrical microstructures contribute to the animal’s ability to create brighter lights. The first reason is that the majority of the surface area in the asymmetrical microstructures allows the animal to have greater interaction with the light it produces from the inside. Because of this interaction, there is less light trapped within the firefly’s body, thus allowing the light to shine with transparency.
The second reason for it is that because of the asymmetrical and mirror-like appearance of the microstructures, the light would often reflect on the microstructures, thus increasing the intensity of the light’s brightness. To have a much better understanding of this phenomenon, imagine that you are surrounded by multiple mirrors in a dark room. If you turn on a flashlight and direct its light to one of the mirrors, but at a slight angle, you will notice that the light would bounce off or reflect towards the other mirrors, and the room would turn brighter. That is how the microstructures increase the intensity of the firefly’s light.
Before finalizing the research paper, the researchers started creating computer-based simulations to see if they can apply the asymmetrical microstructures of the firefly on a LED bulb. After proving that it can indeed be copied on the simulation, they started working on a function LED bulb that features the microstructures. To create the unusual LED bulb, the researchers utilized a nanoscale 3D printer for them to also have an easier and faster time building the exact copy of the one that they created in the computer-based simulation. Besides the asymmetrical LED bulb, they also printed the same object but with a symmetric surface so they can compare the brightness between the two. After several tests, they have confirmed that the asymmetrical LED bulb produced a more intense and brighter light than the symmetrical LED bulb.
After publishing their research, the group of Penn State University researchers applied a patent for their invention in 2019. During an interview in the same year, the researchers said that once they have obtained a patent for the LED bulb, they are willing to have communications with several leading light manufacturers who might want to sell the asymmetrical invention. As of 2020, the patent for the firefly-inspired LED bulb is not yet granted, but because of its speculated impact in the light industry, the patent may be obtained by the researchers sooner rather than later.