Research Interests

My research topics are classified into 2 areas; one is related to fabrication of micro structure, and the other is development of fabrication processes of functional and flexible material. See the following sections for details.

Micro Imprinting Process

A traditional forging process for metal materials could be used to make patterns in nano- or micro- scales. In my topic, compound materials, mixtures of nano ceramic or glass powder material and polymer binder material, are employed. A compound sheet is pressed by a micro-patterned mold to transcribe the pattern, and the sheet is heated subsequently. The polymer binder will be completely removed by the heating, and the nano-powder structure becomes a dense sintered sheet with the pattern.

  • Improvement of SOFC by mirco patterning of interfaces (10.7567/JJAP.56.06GL04, 10.1049/mnl.2013.0310)

  • Formation of micro channels in a glass chip (10.7567/JJAP.54.06FM03 , 10.2497/jjspm.63.511)

  • Imprint process for various patterns such as hierarchical pattern and over-hanged pattern (10.1051/mfreview/2015008 )

An X-CT image of a ceramic chip is shown here. A wavy surface was imprinted, and wavy micro channels, which were 20 micrometer thickness, also observed in the chip.

Magnetic Gel or Elastomer

Magnetic particles are dispersed with gel or elastomer to obtain a magnetic and flexible material. The magnetic response could be controlled by applying a magnetic field during curing process of matrix so that magnetic anisotropy could be set in the material. This anistorpy could be used to make more complex motion of the structure.

  • Bio-mimic applications such as crawler and cilia (10.1149/2.0361909jes, 10.2494/photopolymer.31.121, 10.7567/JJAP.55.06GP19 )

  • Energy harvesting (10.7567/JJAP.57.06HJ05)

Magnetic flexible structure actuated by switching the vertical magnetic field. Four different magnetic orientations were set in black segments.

4D Printer

3D printers are now popular, which can print out 3D objects. Recently, 4D printer has been proposed. 4D printer outputs 3D object which can move as designed. It means addition of the dimension of "time" to 3D spacial dimensions so that it is named "4D printer".

Tsumori's group is now developing a new 4D printing system which employs magnetic flexible material as described above.

  • Bio-mimic application (10.1149/2.0361909jes)

This is a demonstration of 4D printing system by magnetic actuation. A worm-like structure was printed and actuated in between a gap under a rotating magnetic field.

Bio-inspired

Natural creatures inspire engineers. Some topics are ongoing.

  • Crawling motion of soft creatures

  • Bio-inspired surface patterning using imprint technique

  • Glass micro channels manufacturing by "live plants" (10.7567/JJAP.57.06HJ07 )

A plant-root-shaped channel in a transparent glass chip. A plant was cultivated into nano glass powder, and subsequently the sample was heated to burn out the plant and to sinter the glass powder structure. A very fine micro structure was remained in a sintered glass chip.