Advances in cell culture technology have improved the understanding of the physiological principles of cells. Recently, the development of microfluidic chips has made it possible to observe single cells in a massively parallelized and accurate manner. However, in order to maximize the availability of the microfluidic cell chip, it is essential to use an incubator that can isolate the cell culture chip from the outside while minimizing contamination and maintaining the temperature and humidity required for cell culture for a long time period. Here, we developed a thermo-hygrostat incubator consisting of an Arduino-based feedback control module for controlling a temperature and humidity complex sensor, a humidifier, and a heater. The temperature and humidity of the incubator could be actively changed according to the needs and application by simple editing control variables of Arduino coding. To demonstrate the efficiency of the device, we conducted an experiment comparing the growth of bacterial cells and obtained optimal conditions necessary for culture. In conclusion, it is expected that the newly developed thermo-hygrostat incubator can be used for a variety of purposes that require active control of temperature and humidity, as well as for long-term cultivation of bacterial cells inside a microfluidic chip.

The hydrophilicity of the cell culture substrate was controlled by depositing it on the alumina surface through the laser-induced backward transfer (LIBT) method. Alumina particles were sized using laser energy density and deposited on the soda lime glass surface. The particle size and hydrophilicity of the alumina deposition surface were evaluated by measuring the surface roughness, contact angle, and light diffusivity. As the particle size increased, the effect of alumina became stronger, and the deposited surface had relatively higher roughness, stronger hydrophilicity, and higher light diffusivity. The stronger the alumina effect, the lower the growth of Staphylococcus aureus on the deposited surface. In this study, it was confirmed that selective bacterial growth and culture could be controlled by adjusting the strength of the alumina coating using the LIBT process.