An intelligent droplet sorter using optimized liquid-metal electrodes for droplet sorting under a low voltage

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-11, Vol.419, p.136408, Article 136408
• Main Authors: Liu, Qingqing, Guo, Kefan, Jiang, Lin, Yang, Hang, Ni, Zhonghua, Xiang, Nan
• Format: Article
• Language: English
• Subjects: Intelligent droplet sorting; Liquid metal; Low voltage; Numerical simulations; Optimized electrodes
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2024.136408

The sorting of target droplets is an essential function in droplet microfluidics. Previous dielectrophoresis-based droplet sorters were often designed based on experience and required ultrahigh driving voltages of more than 1 kV. In this study, an intelligent droplet sorter (IDS) using optimized liquid-metal electrodes was developed for droplet sorting at a low voltage of 80 V. To explore the optimal structure, we carried out numerical simulations to optimize the dimensions, shapes, and layouts of the electrodes. The optimized IDS with a square active electrode and two pairs of shielding triangular electrodes was obtained based on the normalized dielectrophoresis force ξ and comprehensive efficiency η. Subsequently, the optimized electrodes made of liquid metal were used to deflect droplets under a low driving voltage of 80 V. Finally, we integrated our IDS with an intelligent droplet detection system and successfully applied the system for the sorting of target-encapsulated and empty droplets with encapsulation and collection efficiencies of over 90 %. Our IDS offers the advantages of low voltage, easy fabrication, and excellent performance and thus shows significant potential in sorting target droplets. •Numerical simulations were carried out to optimize the dimensions, shapes, and layouts of the electrodes.•The optimized electrodes made of liquid metal were used to deflect droplets under a low driving voltage of 80 V.•The intelligent droplet sorter and the intelligent droplet detection system were integrated to sort target-encapsulated droplets and remove empty droplets. Both the encapsulation efficiency and collection efficiency were higher than 90 %.