Prediction and control of microparticles in microfluids
・Micro mixing
We are researching a "micromixer" that efficiently mixes very small amounts of liquid. For example, in a blood test, blood and reagents are mixed and reacted, and then analyzed. If analysis can be performed in a small amount, the burden on the patient and the cost of test drugs can be reduced.
We (a collaborative research with Hiroaki Suzuki Laboratory of Chuo University) made a 100 micrometer pillar
(projection) in a micro container of a few millimeters of cubic meters (1/1 million liters) and rotated the
container itself. Then, we devised a method of efficiently mixing the liquid and particles contained in the
container.
Conventional micromixers required a long flow path and ancillary structures such as pumps, but
this method is extremely simple in structure and small in size, and has a high degree of mixing.
When we actually created this container, rotated it, and observed the mixing state with a confocal microscope
and high-speed camera, we found that a circulating flow was formed around the pillar.
In the future, we aim
to find the optimum container and pillar shape, vibration mode, etc. by applying the inverse analysis tool
developed in our laboratory. This is also a research that leverages the strengths of our laboratory, which can
perform everything from optimization to verification experiments.
(left)Particle behavior and (right)simulation of flow and particle trajectories around
array of micro-pillars subject to rotational vibration
(Collaboration with Prof. Hiroaki
Suzuki at Chuo University)
Reference: Kaneko et al. (Micromachines, 2018)
A numerical simulation of pumpless-chaotic micromixer utilizing the vibration-induced
flow
Presentation at Cheminas 44(Nov 9-11, 2021) by Kanji Kaneko
・Array of fine particles
A “confocal microscope” that allows you to scan the three-dimensional space and see the
three-dimensional particle distribution.
This device is used to observe the dynamics of molecules in
solution.
It is a familiar phenomenon, but when the coffee drips that have fallen on the table dries, the
coffee particles become uneven and ring-shaped stains appear on the outer edges of the drips. Why does such a
phenomenon always happen? How do the particles in the liquid move as the solution flows and evaporates?
In
this research, we aim to model the movement of particles in a liquid and ultimately control the particles
freely.
There is a process to apply particles thinly and evenly and evenly by applying a solution by manufacturing and
processing technology such as film, thin film, surface treatment.
For example, electrodes that determine
the performance of fuel cells, solar cells, and lithium-ion batteries form a thin film by applying a slurry
containing fine particles of a material onto a substrate and drying it. If the fine structure of the thin film
can be controlled with high precision, the performance of the battery can be dramatically improved.
We
believe that this research will be useful for optimizing the machining process that was performed based on
experience.
・Topology optimization of interface structure
Topology Optimization of Electrolyte-Anode
Interface in solid oxide fuel cell
Left) Problem setting, Middle) Optimization from different
initial conditions (color: iso-surface of potential),
Right) Interfacial structures and potential
distributions at the bottom
(Collaboration with Prof. Naoki Shikazono at Institute of Industrial
Science, The University of Tokyo)
Reference: Onishi et al. J. Electrochem. Soc (2019)
Poster
