Ko Juhee, Lee Bong Jae, Lee Jungchul
Department of Mechanical Engineering, Center for Extreme Thermal Physics and Manufacturing, Korea Advanced Institute of Science and Technology (KAIST), 34141 Daejeon, Korea.
Microsyst Nanoeng. 2023 Oct 10;9:127. doi: 10.1038/s41378-023-00575-3. eCollection 2023.
For simultaneous and quantitative thermophysical measurements of ultrasmall liquid volumes, we have recently developed and reported heated fluidic resonators (HFRs). In this paper, we improve the precision of HFRs in a vacuum by significantly reducing the thermal loss around the sensing element. A vacuum chamber with optical, electrical, and microfluidic access is custom-built to decrease the convection loss by two orders of magnitude under 10 mbar conditions. As a result, the measurement sensitivities for thermal conductivity and specific heat capacity are increased by 4.1 and 1.6 times, respectively. When differentiating between deionized water (HO) and heavy water (DO) with similar thermophysical properties and ~10% different mass densities, the signal-to-noise ratio (property differences over standard error) for HO and DO is increased by 9 and 5 times for thermal conductivity and specific heat capacity, respectively.
为了对超小液体体积进行同步和定量的热物理测量，我们最近开发并报道了加热流体谐振器（HFRs）。在本文中，我们通过显著降低传感元件周围的热损失来提高HFRs在真空中的精度。定制了一个具有光学、电气和微流体通道的真空腔，以在10毫巴条件下将对流损失降低两个数量级。结果，热导率和比热容的测量灵敏度分别提高了4.1倍和1.6倍。当区分具有相似热物理性质且质量密度相差约10%的去离子水（H₂O）和重水（D₂O）时，H₂O和D₂O的热导率和比热容的信噪比（特性差异与标准误差之比）分别提高了9倍和5倍。
