Temperature sensing system with ultra-high resolution for elucidating the intracellular heat transfer mechanism

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02588
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 28050:Nano/micro-systems-related
• Research Institution: Tohoku University
• Principal Investigator: Inomata Naoki 東北大学, 工学研究科, 准教授 (40712823)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: マイクロナノ温度センサ / 細胞 / 温度信号 / MEMS / 微細加工技術

Outline of Final Research Achievements

We developed a cellular temperature measurement device with a high temperature resolution. Using this device, the thermal properties of single cells were evaluated based on their temperature responses. Measurements were taken under varying surrounding temperatures and frequencies of local heating with a focused infrared laser on cells prepared on the sensors. Frequency spectra were used to determine the intensities of the temperature signals with respect to heating times. Signal intensities at 37 °C and a frequency lower than 2 Hz were larger than those at 25 °C, which were similar to those of water. The thermal conductivity and specific heat capacity, which were determined at different surrounding temperatures and local heating frequencies, were lower than and similar to those of water at 37 °C and 25 °C, respectively. Our results indicate that the thermal properties of cells depend on both temperatures and physiological activities in addition to local heating frequencies.

Free Research Field

マイクロナノ工学

Academic Significance and Societal Importance of the Research Achievements

細胞が環境温度に対して，熱伝導率と比熱を変化させ，周囲の熱的な状況に都度適応していることが明らかになった．特に活性温度である37℃時の熱伝導率は加熱周期にも影響を受けたことから，何かしらの生理現象が誘発され，さらに，加熱周期によって誘発される現象が異なっていることが推測される．また，環境温度25℃時では水の熱物性値と同程度の値となり，これは的には水と大差ないことを意味する．化学固定によって細胞を熱的に不活性な状態にすると，熱伝導率が水と同程度になることは既に報告されており，本研究の成果では環境温度を下げるだけで熱的に不活性な状態を得ることができる可能性が示唆された．