In this paper, we propose a new method to assemble microstructures made of a thermoresponsive gel using hysteresis character of the thermoresponsive polymer solution. This method can be used for 3 dimensional cell assembly by embedding cells in the thermoresponsive gel structures. Gel blocks can be maintained the gel condition by the hysteresis character and the microstructures can be formed by assembling the gel blocks. The temperature distribution around a microheater was analyzed to generate the thermoresponsive gel and avoid thermal damages to cells. The generation of thermoresponsive gel was conducted using the microheater which was embedded in a probe tip and manipulated by a micromanipulator. The fabrication of a gel block was achieved using the hysteresis character and the fabricated gel block was picked and placed by the probe. Cells were embedded in the gel by controlling the position of microheater to avoid the influence of thermal convection flow. The positioning of the gel blocks can be precisely controlled by the micromanipulator. The results indicate the method we propose has a great possibility to achieve 3D cell assembly without large stress to cells during the assembly and cell culture.

In this paper, we conducted an assembly of microstructures made of a thermoresponsive gel using hysteresis character of the thermoresponsive polymer solution. This method can be used for 3 dimensional cell assembly by embedding cells in the thermoresponsive gel structures. Gel sheets can be fabricated by micrheaters on a substrate and maintained in the gel condition by the hysteresis character. The microstructures can be formed by assembling the gel sheets using a probe device. The generation of a thermoresponsive gel was conducted using the microheaters made of ITO on a substrate and the generated gel sheets were manipulated by a micromanipulator. The fabrication of a gel sheets was achieved using the hysteresis character and the fabricated gel sheets were picked and placed by the probe. The positioning of the gel blocks can be precisely controlled by the micromanipulator. The results indicate the method we propose has a great possibility to achieve 3D cell assembly without large stress to cells during the assembly and cell culture.

We proposed a micro fluidic device to control the position of Caenorhabditis elegans (C. elegans) and to analyze the condition of C. elegans as a bioindicator during its lifespan. In this device, we can filter C. elegans depending on size and control the position of C. elegans to culture and test C. elegans and to measure the capacitance change. The capacitance change depends on the body volume of C. elegans. Through the correlation with the capacitance change and the body volume of C. elegans, the body volume of C. elegans is assessed without imaging system. The proposed micro fluidic device was implemented using a PDMS layer and a glass substrate that were bonded together. The PDMS layer had a valve system and pattern rows to filter, culture and test C. elegans. A pair of electrodes is used to measure the capacitance change. In this study, we filtered C. elegans into the same size by filter and one C. elegans was introduced into a chamber row to be cultured and tested. And it was confirmed the correlation between the capacitance change and the body volume of C. elegans. And the proposed micro fluidic device will be applied to observe the effect of chemical or toxicant like heavy metal (Cd) on C. elegans as bioindicator.

This paper presents a novel selective nano-injection method using fluorescent nanobeads based on nanomanipulation for in-vivo single cell analysis. The nanomanipulation system was constructed under hybrid microscope. The hybrid microscope consists of the optical microscope (OM) and environmental-scanning electron microscope (E-SEM) to realize biological specimen analysis by optical imaging including fluorescent imaging, and nano-scale manipulation by E-SEM imaging. Based on the bio-nano manipulation system, we propose a nanoinjection method by nanoprobe insertion and nanobead embeddedness. The nanoprobe was designed to have four tips to fix single nanobead. It is fabricated by focused ion beam (FIB) process. Its nano-scale size is considered to be important for minimal damage to a biological specimen. In this work, as biological specimen, the Caenorhabditis elegans (C. elegans) was used. It is one of the important model organisms for various diseases analysis. The nanoinjection technique is applied to transport fluorescent materials or specific biological organism into a specific cell for in-vivo experiment of C. elegans. The proposed system is considered to be important as future nano-surgery system for life innovation using model organism.

For tissue engineering, it is very important to construct cell patterns and immobilize patterned cells inside certain structures. In this paper, we present methods of forming cell pattern by dielectrophoresis (DEP) and immobilizing cells by photo-crosslinkable resin inside microfluidic chips. High speed cell manipulation, including patterning and concentration control by DEP is demonstrated. Movable microstructure embedding cells is on-chip fabricated. Several microelectrodes are fabricated by Indium Tin Oxides (ITO) and Cr/Au. The two kinds of DEP responses of yeast cell (W303) and other particles are experimentally confirmed. Based on negative DEP phenomenon, line and circle patterns of cells and microbeads are high speed performed. Cell manipulation for patterning is completed within 1 second. The on-chip fabrication of movable microstructures embedding cells based on Poly Ethylene Glycol Diacrylate (PEG-DA) is reported. The microfluidic chip with separated patterning and fabrication areas is fabricated. With the cell concentration control by DEP and on-chip fabrication method, movable microstructures embedding microbeads of which the concentration is controllable are fabricated in the microfluidic channel, inside PEG-DA and NaCl solution.