Separation of microalgae cells in a microfluidic chip based on AC Dielectrophoresis

Abstract

BACKGROUND Microalgae is an important natural resource with extensive applications in various fields, such as health products, animal feed, biopharmaceuticals, and clean energy. However, before the research and utilization of microalgae resources, the microalgae cells of interest must be separated from hybrid strains and bacteria. The traditional method of microalgae separation requires manual labor under the microscope that is time‐consuming and labor‐intensive. RESULTS Herein, a novel microalgae cell separation method based on the dielectrophoresis (DEP) technique was proposed. A unique DEP separation chip with a 3D electrode was designed. Chlorella and Closterium were used as the experimental samples to verify the effectiveness of the proposed method because they have similar volumes and very different electrical properties. Within a certain frequency range, Chlorella suffers from negative dielectrophoresis (nDEP) force and Closterium suffers from positive dielectrophoresis (pDEP) force, so their separation can be achieved. The separation efficiency exceeded 90%. In addition, the DEP response of the Chlorella and Closterium were studied, and the DEP spectra of the two microalgae cells were obtained. Moreover, the effects of DEP force on cell viability under different voltages and frequencies were experimentally analyzed. CONCLUSION These findings will contribute to DEP technology, to the portable and harmless separation of microalgae, and to research on the dielectric properties of microalgae cells. © 2022 Society of Chemical Industry (SCI).

DC-Dielectrophoretic Manipulation and Isolation of Microplastic Particle-Treated Microalgae Cells in Asymmetric-Orifice-Based Microfluidic Chip

“…Microalgae are widely distributed around the world, and they are rich in protein, biological antibiotics, and oil [ 1 , 2 ], which are widely utilized in various fields, such as biotechnology, the food industry, and environmental protection [ 3 , 4 , 5 ]. As microalgae show outstanding biological properties, including high photosynthetic efficiency and simple structure, they can grow well under extreme environmental conditions of heavy metals, high salinity, nutrient deficiencies, and extreme temperatures.…”

Virtual Filter Membranes in a Microfluidic System for Sorting and Separating Size-Based Micro Polystyrene Beads by Illumination Intensity Design in Optically Induced Dielectrophoresis (ODEP)

“…To solve the limitations of conventional filtering membrane-based isolation methods, a DEP technique embedded in a microfluidic system has been proposed for the isolation and purification of bioparticles as a new platform for filtering membranes [13]. Particle manipulation using the DEP working mechanism was first proposed by Herbert A. Pohl in 1951 [14].…”

“…Therefore, many designs of metal microelectrode arrays are used to control the electric field to manipulate these particles for specific applications, including particle patterning [15], enrichment [16], and classification [17]. The integration of metal microelectrode arrays as a controllable filtering membrane and DEP force-based manipulation in a microfluidic system is believed to be a potentially effective solution for the isolation and purification of bioparticles, which can have fewer blocks by the release of particles with a properly applied external electric field [13]. Reports in the literature have also demonstrated the use of this technique for a wide variety of biological applications, including the centration of specific cells [18], removal of bacteria in the water [19] and isolation of CTCs from cancer patients' blood samples [20].…”