Research (Inomata Lab.)

Creation of Ultimate Sensing Technology: Enabling Measurements Beyond the Technical Limits

My topics are research in engineering and technology to develop advanced sensors enabling measurements of physical phenomena that could not be observed with existing technologies. Microsensors, which are extremely small at less than 0.1 mm (equivalent to the diameter of a human hair), can detect minute physical changes precisely because of their small size. By integrating mechanical, electrical, and optical technologies, I realize human sensing for measuring biomolecules, cells, and humans, as well as man-machine interfaces based on the obtained knowledge. The research is broadly categorized as [Biological Measurement and Analysis Technology][Metamaterials] [Development of Novel Principle Sensors].


*The Inomata Lab. is actively recruiting students for the doctoral course both domestically and internationally. Click here for information on Tohoku University's financial support.

[Biological Measurement and Analysis Technology]

Dynamic measurements of cellular temperature for determining the thermal properties.

Background: Achieved precise measurement of thermal properties with temperature resolution and time response unattainable by conventional methods.
Findings: Discovered that cells themselves change their thermal conductivity and specific heat depending on the ambient temperature and heating duration.

Cos7 cell on the sensor (left) and image of cell heating (right) Cellular thermal conductivity and measurement conditions
 Cellular specific heat and measurement conditions

References:
Lab Chip, 23, 2411-2420 (2023)
Sensing and Bio-Sensing Research, 27, 100309 (2020)

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[Metamaterials]

Control of Mechanical Vibration Propagation Using Phononic Metamaterials

Background: Controlling vibration energy is crucial for improving the performance of mechanical resonant sensors. For example, to enhance sensitivity, vibration energy should be retained, while for faster response, energy should be dissipated more quickly.
Findings: Successfully demonstrated, for the first time in silicon (Si), a key material in microsystems, the ability to store and release vibration energy using a microstructure with tunable periodicity (variable phononic metamaterial).

Performance and Features

Fabricated Si phononic metamaterial (the center is mechanical resonator to be used the experiments) Difference in Vibration Energy (Q Factor) in Similar Patternsl
 Difference in Vibration Energy When Stretched

References:
Scientific Reports, 12, 392 (2022)

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[Development of Novel Principle Sensors]

Liquid thermocouple

Background: Ionic liquid thermoelectric materials offer better performance than traditional solid thermoelectric materials. While thermocouples require the contact of dissimilar materials, maintaining an interface between two liquids is challenging.
Findings: Achieved a liquid thermocouple by electrically contacting different ionic liquids using a microfluidic chip. The performance of this liquid thermocouple exceeds that of conventional solid thermocouples by more than ten times.

Image of the proof-of-principle using a microfluidic chip
 Thermocouple using ionic liquids
Output depended on temperature

References:
IEEE Sensors Letters , 3(5), 2501304 (2019)

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