Measurement of fluid thermal conductivity using a micro-beam MEMS sensor

• Published in: International journal of heat and mass transfer Vol. 117; pp. 30 - 35
• Main Authors: Takamatsu, Hiroshi, Wang, Haidong, Fukunaga, Takanobu, Kurata, Kosaku
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2018; Elsevier BV
• Subjects: Feasibility studies; Free convection; Heat conductivity; Heat transfer; Measurement; MEMS sensor; Microelectromechanical systems; Platinum; Silicon substrates; Steady-state measurement; Studies; Thermal conductivity; Steady-state measurement; Thermal conductivity; MEMS sensor
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2017.09.117

•New method was established by demonstrating successful measurement with six fluids.•Measured thermal conductivity agreed with literature values within 4% error.•The method was significantly improved from our previous paper.•The steady-state measurement without the effect of natural convection is unique.•The method using a MEMS sensor has a potential to measure a drop of sample. A new method for measuring thermal conductivities of gases and liquids was established by demonstrating the measurement of five kinds of liquid and air. It uses a sensor named “micro-beam sensor” that is a ∼10-μm-long free-standing platinum membrane suspended across a trench on a silicon substrate and heated in a sample by DC. This method is unique in that it is a steady-state measurement but free from the effect of natural convection owing to the micrometer size of the sensor. Improving the method for precisely determining the temperature of the sensor and modifying the device from those used in our previous feasibility study, we successfully measured the thermal conductivity ranging from ∼0.03 to ∼0.6 W/(m⋅K) within 4% error.