Non-contact quantitative thermal imaging in micro-scale is attractive to realize the non-contact thermal analysis during phase transitions. It visualizes both the temperature field and heat transfer. Here we review the system of IR camera equipped with an original optics and temperature calibration algorithm, which is applicable to achieve the high-quality and fast thermal imaging. The Infrared (IR) optical lens design has been optimized to each wavelength band of the photon type and the thermal type detectors of IR FPA. Typical applications to observe the freezing biological cells are presented. The most recent system enables to visualize the thermal imaging of freezing onionskin cells at 10,000 frames/s during rapid cooling process.

To study the kinetics of phase transitions and to obtain artificial materials with improved physical properties, a set of thin-film high-sensitivity sensors for ultra-fast scanning nanocalorimetry has been constructed. To investigate the dynamics of the temperature distribution in thin-film calorimetric sensors, high-resolution high-speed infrared thermography has been applied as a tool of non-contact thermal imaging in combination with ultra-fast scanning calorimetry.

Non-contact qualitative measurement of the temperature field with Infrared camera based on the thermal radiation measurement has been extensively investigated for the material thermal characterization and observation of the thermal energy transfer in a microscale. Non-contact temperature measurement has the advantage that the sensor itself does not disturb the temperature field in the sample. However, the estimation of the absolute value of the temperature from the thermal radiation is not always possible, especially in the concentration distributed field, such as in a liquid mixture or in the coexistence region of the several phases of the material. This is due to the emissivity distribution of the sample. Microscale thermospectroscopic imaging has been developed for the simultaneous imaging of the infrared spectrum and thermal emission in mid IR region with microscale special resolution. This imaging method was further extended for the quantitative analysis of the concentration and temperature field in organic molecular system, such as phase transition or the chemical reaction in the microfluidics. This imaging method for the temperature estimation is based on the spatial correlation between emissivity distribution and concentration distribution. In this study, generalized analysis method of the thermospectroscopic imaging was investigated, and the analysis of the phase transition and microscale mixing of the liquids are explained by a unified equation for the concentration and temperature dependent IR camera signal.