Fabrication of Microstructures Embedding Controllable Particles inside Dielectrophoretic Microfluidic Devices

Abstract

This paper presents a method of particle manipulation by dielectrophoresis (DEP) and immobilization using photo-crosslinkable resin inside microfluidic devices. High speed particle manipulation, including patterning and concentration control by DEP was demonstrated. Immovable and movable microstructures embedding particles were fabricated onchip. Several microelectrodes were fabricated using Indium Tin Oxides (ITO) and Cr/Au. The two kinds of DEP responses of yeast cells (W303) and other particles were experimentally confirmed. Based on negative DEP phenomenon, cell traps generated by microelectrodes were demonstrated. Position control, transportation and patterning of cells were performed with cell traps. The on-chip fabrication of arbitrary shapes of microstructures based on Poly(ethylene glycol) diacrylate (PEGDA) was reported. With cell patterning by DEP and immobilization using on-chip fabrication, microstructures embedding line patterned cells were fabricated inside microfluidic channels. A novel microfluidic device was designed to separate patterning and fabrication areas and movable microstructures embedding concentration controllable particles were fabricated inside this device.

State of the art: micro-nanorobotic manipulation in single cell analysis

“…DEP has the advantages of noncontact manipulation, good controllability, and high-integration ability within the microchip. Therefore, it has been widely used for cell trapping and sorting, especially for the cell analysis in the microfluidic chip [28,42]. One problem of DEP lies in that the strength of the force strongly depends on the medium and particles' electrical properties, on the particles' shape and size, as well as on the frequency of the electric field.…”

“…(c) Microbeads dancing controlled by the optical tweezers [27]. (d) Cell positioning by dielectrophoresis (DEP) chip [28]. (e) Schematic drawing of the optoelectronic tweezers (OETs) [29].…”

Micro-Assembly of a Vascular-Like Micro-Channel with Railed Micro-Robot Team-Coordinated Manipulation

“…Micro-robot-team assembly of the vascular-like microchannel Figure 17. Observation of the cellular vascular-like micro-channel 16, the 2D donuts (as the assembly components) were prepared in the dish and monitored by the vision feedback system. The outer diameter, inner diameter and thickness of the fabricated donuts were 200 μm, 100 μm and 70 μm, respectively.…”

“…From a fluidic point of view, microfluidic systems have emerged as promising tools in building the pathological models of the vasculature. Through the assembly of three-dimensional (3D) cell structures with the precise manipulation provided by optical tweezers, DEP and fluidic forces, a vascular-like structure can be realized [11][12][13][14][15]. Our team has developed dielectrophoretic microfluidic devices for cell patterning and assembly [16].…”

“…Through the assembly of three-dimensional (3D) cell structures with the precise manipulation provided by optical tweezers, DEP and fluidic forces, a vascular-like structure can be realized [11][12][13][14][15]. Our team has developed dielectrophoretic microfluidic devices for cell patterning and assembly [16]. However, the strict operation requirements and the closed environment of the system hinder flexibility during assembly of the 3D structure.…”