Discipline: Technology and Engineering
Subcategory: Electrical Engineering
Alexander Shammai - Texas A&M University
Co-Author(s): Hyun Soo Kim, Arum Han, Evan Richards, Nida Warsi, and Sergio Waqued, Texas A&M University, TX
Microalgae are seen as potential fountainheads for renewable energy because of the carbon rich, easily refined oil they produce during their growth cycle compared to food-based biofuel feedstocks. However, their biofuel production cost is not economically competitive, requiring significant improvements such as optimization of their cultivation conditions. Conventional microalgae testing platforms (lab-scale flasks, open raceway ponds, or closed photobioreactors) are limited to optimize the culture conditions due to their bulk scale, operating cost, and inaccurate light control. Here we present an automated, compact and inexpensive light-controlling photobioreactor to investigate optimized culture conditions for microalgal growth and oil production. The developed photobioreactor consists of a glass container with a lid that has a mounted multi-wavelength array of LEDs facing toward the sample. The array comprises of three adjacent strips of LEDs, representing different wavelength spectrums (White, Red, and Blue). On the bottom glass container, a holster is designed for the bio-testing platform to be positioned within a uniform light condition region. All LED strips are controlled by an Arduino microcontroller, which can manage light wavelength, intensity, and on/off cycle in the platform. Light wavelength and on/off cycle are controlled by selectively turning on and off a particular LED strip, and light intensity can be changed by driving a different voltage into the LED strips. This new photobioreactor is compact and light due to its fully integrated design. It can accommodate other bio-testing platforms such as microfluidic and microdroplet devices for testing other culture conditions simultaneously. The developed photobioreactor is currently being characterized. Light intensity as well as uniform intensity area were measured by changing the distance from the light source to sample and the driving voltage to LEDs. Parabolic relation (intensity vs. distance) and linear relation (intensity vs. voltage) were observed, and 20° of angular displacement for uniform intensity area was measured regardless of light intensities. The control of light wavelength, cycle, intensity in the LED strips was tested with Arduino, and currently a userfriendly GUI is being programmed. This photobioreactor, in conjunction with culture platforms, will be utilized to optimize the light conditions of various microalgal strains for improved growth and oil production.
Funder Acknowledgement(s): This study was supported by a grant from NSF/EFRI-REM awarded to A. Han.
Faculty Advisor: Arum Han, firstname.lastname@example.org