Synthesis of copper nanoparticles using microfluidic device
Copper nanoparticles (CuNPs) are attracting attention as ink materials with lower cost than silver and excellent in performance such as electrical conductivity. However, since copper is easily oxidized, synthesis in an inert atmosphere is necessary, and the particle size depends on the reduction temperature. It is expected that since the microfluidic device is sealed from the outside and the thermal efficiency is high, it is possible to control the particle size of CuNPs by changing the temperature and the flow rate in the microchannel.
Synthesis of gold nanoparticles dispersion in organic solvent using microfluidic device
In the Brust-Siffrin method (Brust method), an immiscible solution consisting of an aqueous solution and a toluene solution is vigorously stirred in the presence of a protective agent after an aqueous gold ion solution is transferred to a toluene phase (organic phase) using a phase transfer catalyst, and then gold nanoparticles dispersion in toluene can be synthesized by adding an reducing agent solution. In the case of synthesizing nanoparticles by Brust method using a beaker, since the particle size depends on the addition rate of the reducing agent, the stirring speed, and the stirring time, it is difficult to control particle size. Since the flow state of immiscible solution in the microchannel depends on the flow rate, the particle size of the synthesized nanoparticles by adjusting the flow rate. In this study, we investigated the visualization of the flow state of the immiscible solution in the microchannel, and the relation of the flow rate and the coefficient of variation (standard deviation / mean diameter) was clarified.
DNA nanostructure
The double stranded DNA model was created for production of DNA nanostructure applied DNA origami technology. The model with electrostatic interaction was discussed. We confirmed that the dependency of the salt concentration on the persistence length of the nCG-dsDNA model at the 30% charge is in good agreement with the Poisson–Boltzmann theoretical model.
Laser microfabrication process
Laser microfabrication of goid nanoparticles dispersed polymer film is prposed. Since wave length of laser beam is selected an absorption wavelength by plasmon resonance vibration of gold nanoparticles, the polymer film can be micromachined. In this study, we focus the effect of size and distribution of naoparticle on laser processed shape.
Analysis of gold nanoparticles synthesis mechanism using microfluidic device
A glass microfluidic device with mcirochannel is fabricated by micropowder blasting, and the prepareation of metalic nanoparticles on the produced device is prposed. In this study, we focus the production of device which can synthesize nanoparticles by liquid-phase reduction method.
Simulation of polymer resist for MEMS
The mechanical property of the polymer resist is required for development of MEMS microfluidic device. We predict the relationship between the mechanical property and the structure of resist in molecular scale by coarse grained molecular dynamics simulation.
Simulation of rubber materials
A polymer chain is treated as a simple beads-spring model, and the viscoelastic and elongation behavier of the model is simulated using molecular dynamics calculation software such as OCTA/COGNAC and LAMMPS with supercomputer according to the model scale.
Simulation of micropowder blasting
We predict processed shape on a glass substrate by powder btasting using cellular automaton method. The simulator is improved by comparison of experimental result and simulated result, in addition of the production of processing system.