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The 3D assembly of micro-/nano-building blocks with multi-nanomanipulator coordinated manipulation is one of the central elements of nanomanipulation. A novel rail-guided nanomanipulation system was proposed for the assembly of a cellular vascular-like hydrogel microchannel. The system was equipped with three nanomanipulators and was restricted on the rail in order to realize the arbitrary change of the end-effectors during the assembly. It was set up with hybrid motors to achieve both a large operating space and a 30 nm positional resolution. The 2D components such as the assembly units were fabricated through the encapsulation of cells in the hydrogel. The coordinated manipulation strategies among the multi-nanomanipulators were designed with vision feedback and were demonstrated through the bottom-up assembly of the vascular-like microtube. As a result, the multi-layered microchannel was assembled through the cooperation of the nanomanipulation system.

The 3D assembly of cellular structures is important for the fabrication of biological substitutes in tissue engineering. In particular, a micro-channel with a 200 μm diameter is of interest because of its promising ability to construct the vascular network for oxygen and nutrition delivery in thick biological substitutes in the future. In this paper, a novel rail-guided micro-robot-team system is proposed for the micro-assembly of a cellular structure. The cellular two-dimensional (2D) component was fabricated by ultraviolet (UV) illumination of a cross-linkable hydrogel. The modular rail-guided micro-robotic system was set up with multi-micromanipulators as the modules and controlled with hybrid motors to achieve an operation resolution of 30 nm. To realize the bottom-up fabrication of the cellular micro-channel, different micro-assembly strategies with multi-manipulators were developed. The micro-assembly success rate and the efficiency of the different strategies were evaluated based on the assembly of micro-donuts. Through the novel, designed, concentric movement of the multi-manipulators along the rail, arbitrary change of the approaching angle and the coordination posture was achieved to improve the micro-assembly's flexibility. The operation range for every micromanipulator in different coordinated manipulation modes was analysed to avoid the breakdown of the assembled 3D structure. The image processing for the target location and end-effector identification was conducted to improve assembly efficiency in the micro-robot-team system. Finally, the assembly of the cellular vascular-like micro-channel was achieved with coordinated manipulation in the rail-guided micro-robot-team system.

In this paper, we present the fabrication and assembly of microstructures inside a microfluidic device based on a photocrosslinkable resin and optical tweezers. We also report a method of solution replacement inside the microfluidic channel in order to improve the manipulation performance and apply the assembled microstructures for single cell cultivation. By the illumination of patterned ultraviolet (UV) through a microscope, microstructures of arbitrary shape were fabricated by the photocrosslinkable resin inside a microfluidic channel. Based on the microfluidic channel with both glass and polydimethylsiloxane (PDMS) surfaces, immovable and movable microstructures were fabricated and manipulated. The microstructures were fabricated at the desired places and manipulated by the optical tweezers. A rotational microstructure including a microgear and a rotation axis was assembled and rotated in demonstrating this technique. The improved laser manipulation of microstructures was achieved based on the on-chip solution replacement method. The manipulation speed of the microstructures increased when the viscosity of the solvent decreased. The movement efficiency of the fabricated microstructures inside the lower viscosity solvent was evaluated and compared with those microstructures inside the former high viscosity solvent. A novel cell cage was fabricated and the cultivation of a single yeast cell ( w303 ) was demonstrated in the cell cage, inside the microfluidic device.

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 on-chip. 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.