Microfluidic Platform for Microalgae Cultivation under Non-limiting CO2 Conditions

Microfluidic platforms for microalgae cultivation can be exploited to intensify data collection and enhance the ability to control the most relevant operational parameters. In this work, a new array of micro-photobioreactors (mPBR) was designed to supply a continuous flow of nutrients; CO2 is the main substrate for photosynthesis, but its supply in nonlimiting concentration to microdevices can represent a design challenge. To address this issue, a preliminary CO2 absorption phase was exploited. This carbon-rich liquid stream was then delivered to the mPBR, where it diffused to the culture wells. The device was tested with Scenedesmus obliquus using in vivo chlorophyll fluorescence measurements for growth monitoring. Results demonstrated that the experimental setup is effective at delivering CO2 inside the mPBR. Tests at different incident light intensities showed the mPBR applicability to describe light effects on cell growth, without carbon and nutrient limitations and undesired self-shading effects.