The plasma jet has been proposed as a novel therapeutic method for anticancer treatment. However, its biological effects and mechanism of action remain elusive. Here, we investigated its cell death effects and underlying molecular mechanisms, using air and N₂ plasma jets from a micro nozzle array. Treatment with air or N₂ plasma jets caused apoptotic death in human cervical cancer HeLa cells, simultaneously with depolarization of mitochondrial membrane potential. In addition, the plasma jets were able to generate reactive oxygen species (ROS), which function as surrogate apoptotic signals by targeting the mitochondrial membrane potential. Antioxidants or caspase inhibitors ameliorated the apoptotic cell death induced by the air and N₂ plasma jets, suggesting that the plasma jet may generate ROS as a proapoptotic cue, thus initiating mitochondria-mediated apoptosis. Taken together, our data suggest the potential employment of plasma jets as a novel therapy for cancer.

A new micro cell chip which can induce stem cells to differentiate into specific body cell types has been designed and fabricated for tissue engineering. This paper presents the test results of a micro cell stimulator which can provide a new miniaturized tool in cell stimulation, culture and analysis for stem cell research. The micro cell stimulator is designed to apply compressive pressure to the hMSCs (human mesenchymal stem cells) for inducing osteogenesis. The micro cell stimulator is based on the pneumatic actuator with a flexible diaphragm which consists of an air chamber and cell chambers. The hMSCs under cyclic compressive stimulation for one week were observed and assessed by monitoring CD90 (Thy-1), actin, alkaline phosphatase (ALP) and alizarin red expression. The results suggest that cyclic mechanical stimulation is attributed to the different phenomenon of cultured hMSCs in cell proliferation and differentiation. These results are important for the feasibility of the micro cell stimulator to provide the reduction of the necessary quantity of cells, process cost and the increase of the throughput.

A 440 MHz wireless and passive surface acoustic wave (SAW) chemical sensor was developed for CO₂ detection. The developed SAW gas sensor is composed of single phase unidirectional transducers (SPUDTs), three shorted grating reflectors, and CO₂-sensitive polymer film on 41° YX LiNbO₃ substrate. Coupling of modes (COM) modeling was used to find optimal design parameters. Using the extracted design parameters, the SAW device was fabricated. Teflon AF 2400 was used as the sensitive film because it provides high CO₂ solubility, permeability and selectivity. In wireless device testing using a network analyzer, four sharp reflection peaks with high signal-to-noise (S/N) ratio, small signal attenuation, and few spurious peaks were observed in the time domain. The time positions of the reflection peaks were well matched with the predicted values from the simulation. Infusion of CO₂ into the chamber induced large phase shifts of the reflection peaks. Good linearity and repeatability were observed for a CO₂ concentration of 0–450 ppm. The obtained sensitivity was 1.98° ppm⁻¹. Temperature and humidity effects were also investigated during the sensitivity evaluation process.

This review gives an overview of the development of surface acoustic wave (SAW) based gyroscopes. Different types of SAW based gyroscope are first presented, which are categorized into standing-wave based or progressive-wave based gyroscopes according to their respective mechanisms. In addition, multi-axis detectable SAW based gyroscopes are also introduced in this review. Different principles, structures, production methods, and control technologies are analyzed.