Microfluidic systems for microalgal biotechnology: A review

Microalgae have a demonstrated potential as producers of high-quality renewable biofuel feedstocks as well as other high-value chemicals. However, significant improvements from microalgal biology and strain development to downstream processing are required to achieve economically viable microalgae-derived biofuels and bioproducts. Mainstream techniques used in microalgal research are based on conventional cell culture and cell handling systems, which are bulky, labor-intensive, time-consuming, and also limited in throughput. Microfluidic lab-on-a-chip systems can offer cost- and time-efficient alternatives to advance microalgal biofuel and bioproduction research by providing high precision and high efficiency cell/reagent handling capabilities, enabling high-throughput assays in a fully automated fashion. Here, we review recent advances in the development and application of microfluidic lab-on-a-chip systems for microalgal biotechnology, especially microalgae-based biofuels, including microsystems for single-cell resolution high-throughput cell identification and separation, highly efficient cell transformation, high-throughput parallel cell cultivation, cell harvesting, and cell analysis applications. Other microfluidic applications such as microalgae-based fuel cells and microalgae-based biosensing platforms are also reviewed towards the end. We conclude by suggesting possible future directions on how microfluidic lab-on-a-chip systems can be utilized to overcome current challenges and improve the current status in microalgal biotechnology.