Project Motivation and Description:
Hybrid Fiber Optic LED lighting was the topic of my primary masters research work at Cornell University. Countless studies dating back several decades have proven that quality lighting and daylighting can have drastic impacts on human efficiency, wakefulness, healing, and more. With respect to building efficiency, approximately 40% of building energy is generally consumed solely by lighting. Surprisingly, most of this energy usage happens during daylight hours, when the sun is out and could be providing much of the light needed in most scenarios. I devised a system to permit the transmission of natural sunlight into any room in any building using fiber optic transport cables coupled with auxiliary color-tuned LED lighting. When natural sunlight is available, a solar tracking heliostat equipped with an array of light-collecting lenses focuses light into fiber optic cables that transport it to “luminaires” throughout a building for reemission as indoor lighting. To accommodate for cloudy days, nighttime, and other conditions that result in inadequate light being available from only natural sources, an intelligent control system is able to determine the amount of additional light needed and use LEDs to supplement the fiber optic natural light. Importantly, these LEDs do not only emulate the quantity of sunlight, they also emulate the quality of sunlight using an array of 4 multi-diode high-intensity color-tuned RGBW (red, green, blue, and white) LED modules that match the color and quality of the sun as it changes over the course of the day and the year. By doing this, the luminaire light fixtures can contribute significant health benefits by emulating the natural daylight conditions that mediate human circadian rhythm by maintaining tight control over the wavelengths of light emission over the course of a day. Using a mobile app, it is possible to manually control the system, adjusting color, intensity, percentage of natural light transmission, and more. The completed system was integrated with work done by Cornell University Sustainable Design, and was installed in an exhibit in Washington, DC, in April, 2013 where it was successfully exhibited. This system won first place at the Annual ECE Day competition as well as several other awards.
Team and Roles:
I served as the primary technical director of this project. Specifically, I designed and manufactured the custom PCBs for the Luminaires, I wrote all the embedded firmware, I wrote the software for both the cloud and local webservers that ran the system, I developed the solar tracking algorithms, I devised the communication system, and I created the mobile web app that controlled everything. I also devised some of the mechanical systems, and tested the fiber optic cables. I did all the 3D-printing required for the project. My teammates handled the luminaire reflector designs (from an aesthetic perspective), mechanical design of the heliostat/collector modules, systems engineering/cost analysis, and exhibit design/construction.
Accolades and Support:
Our Hybrid Fiber Optic LED lighting system was the recipient of a grant from the Environmental Protection Agency – the P3 (People, Planet, and Prosperity) Grant. As a result, we exhibited this system on the National Mall in Washington, DC. I also presented my role in this project for Cornell’s annual ECE (Electrical and Computer Engineering) Day. I made it to the finals, and was then awarded first place from the ECE advisory council.
I might be done with my Master’s degree, but this project is far from over. One of the objectives of the P3 grant is to develop sustainable, commercially-viable technologies, which we aimed to do with this lighting system. In the process of developing the system, we came to the conclusion that Fiber Optics are too expensive to make this system commercially viable. However, utilizing just LEDs, and taking advantage of our novel solar tracking algorithms, we determined that this technology can be applied to traditional residential and commercial lighting systems to improve human health, and to reduce energy consumption. This technology is being spun off into a company, SUNN, of which I am the co-founder and CTO. You can sign up for our newsletter to learn more.
Check out these great photos of our system in action on the National Mall in Washington, DC!