Microparticle Manipulation Based on the Bulk Acoustic Wave Combined with the Liquid Crystal Backflow Effect Driving in 2D/3D Platforms

Abstract

Microparticle manipulation has been widely used in clinical diagnosis, cell separation, and biochemical analysis via optics, electronics, magnetics, or acoustic wave driving. Among them, the bulk acoustic wave (BAW) driving method has been increasingly adopted because of non-contact, easy control, and precise manipulation. However, its low manipulation efficiency limits the usage of the BAW driving in high viscosity solutions. Therefore, in order to obtain larger driving force and more flexible manipulation of microparticles, both two-dimensional (2D) and three-dimensional (3D) platforms based on the BAW and liquid crystal backflow effect (LCBE) driving in liquid crystal (LC) solutions are proposed. The driving forces applied on the microparticles allow for the change of microparticle moving direction, which is also ascertained through theory analysis combined with various driving methods. Specifically, the maximum moving speed (68.78 μm/s) of the polystyrene particles is obtained by the BAW (13 Vpp) combined with LCBE (30 V) at a low frequency of 7.2 kHz in the 2D platform. Precise position manipulation in 3D is also fulfilled through a programmable logic control model using polystyrene particles as a demonstration. In addition, red blood cells mixed with LC solutions are arranged in a line or gathered in the pressure nodes of the BAW forces along with sinusoid signals generated by various transducer combinations. Therefore, it is approved that the LC solution that induces the LCBE force could increase the microparticle manipulation efficiency in both 2D and 3D platforms. The proposed method will open up new avenues in particle manipulation and benefit a variety of applications in cell separation, drug synthesis, analytical chemistry, and others.

Fabrication and Separation of EGaIn Microparticles from Human Blood Based on Dielectrophoresis Force and a W-Type Electrode

“…In addition, many methods have been developed to separate heavy metal particles from blood, such as centrifugation, membrane filtration, and dielectrophoresis (DEP) methods. − However, the microparticles or cells are susceptible to surface damage due to direct contact in these methods. On the other hand, DEP originating from non-uniform electric fields has a non-contact feature and thus has been increasingly used in many fields, − including sorting of cells, bacteria, viruses, and other micro/nanoparticles. − For instance, it has been used for isolation of rare cancer cells and circulating tumor cells (CTCs) from blood for early diagnostics. − Song et al developed an angled IDE device to separate human mesenchymal stem cells (hMSCs) from progeny osteoblasts with a throughput of 5.4 μL/min . Chen et al reported a method for label-free, contact-free isolation and recovery of extracellular vesicles via optically induced DEP .…”