The pneumatic vibration isolator is economical, has no risk of contamination, and attains high vibration isolation performance by lowering the natural frequency. Pressure feedback control is used to improve the response speed of the pneumatic vibration isolator and keep the internal pressure of the pneumatic actuator constant. In this paper, the vibration isolator was actively controlled by estimating the internal pressure of the pneumatic actuator with the displacement signal. A pneumatic actuator was modeled and its dynamic characteristics were identified through frequency response measurements. A pressure observer based on relative displacement was designed, and the observer control gain was adjusted with nominal model and experiments. Pressure estimation performance and active vibration suppression performance using a pressure observer were verified through experiments. The pressure of the pneumatic actuator was estimated by the observer, and measurement noise was eliminated effectively. In addition, vibration isolation performances of direct and estimated pressure feedback showed no difference, verifying the effectiveness of the pressure observer.

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.

Recently, instrument stages using flexure guide mechanisms and piezo actuators have been widely used for an ultra-precision positioning system in various industries. Research into ultra-precision position control aiming at nanoscale position errors during stage driving is being actively conducted, as well as various studies on the motion profile adjusting the reference input. In this study, we suggested a motion profile with snap and feedforward for use with a high speed nano scanning system, as compared and analyzed with the position tracking error through feedback control, and also compared to the related feed with the forward control noted as minimized at the position error to 14.19 nm. As a result, a tracking error when applying the fourth profile with snaps to the piezoelectric stage, is obtained with an error reduction effect of about 15%, as compared to when the second profile is applied.