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.

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In this paper, we present an optimized bonding method to bond PMMA and PDMS substrates. Silane primer was used for the formation of hydroxyl groups on PMMA surfaces. The hydroxyl groups enhanced the bonding strength of PDMS-PMMA substrates without channel clogging or structure deformation. X-ray photoelectron spectroscopy (XPS) analysis was performed to identify the fundamental processes for bonding, which were oxygen plasma, 3-APTES, and corona discharge. We characterized the bonding strength in terms of the tensile strength and the leakage pressure for various surface treatment conditions to find optimal bonding process. The average bonding strength obtained by the optimal bonding process is 2.5 MPa. This bonding process using silane primer can be widely used in the microfluidics of micro-total analysis system and lab-on-a-chips.

We propose a micro rate gyroscope (MRG) based on the surface acoustic wave (SAW) gyroscopic effect for extremely high-shock military applications. We not only derived theoretically the SAW gyroscopic gain factor in a ST-cut quartz by introducing a wave velocity ratio and the perturbation method, but also verified this gain factor by experiment. The proposed SAWMRG, which consists of two delay-line oscillators, operates as a differential scheme. To estimate an inherent insertion loss, we adopted the equivalent circuit model in the design process of the delay line. The 9 × 9 mm2 SAWMRG was fabricated on a ST-cut quartz and loaded into a specially designed low temperature co-fired ceramic (LTCC) package to ensure good RF characteristics. The center frequency and the insertion loss of the delay line are measured at 98.6 MHz and 15.2 dB, respectively. We evaluated the performance of the SAWMRG, using a rate table and stochastic noise analysis, revealing a sensitivity of 0.431 Hz deg−1 s−1 in the angular rates up to 2000 deg s−1 and a white noise of 0.55 deg s−1 Hz−1/2, respectively. Consequently the feasibility of the proposed SAWMRG was verified through a set of performance evaluations, confirming the theoretical predictions.

This paper presents the development of a reliable multi-liquid lab-on-a-chip (LOC), with a hand-operated mechanism, for the application in portable immunosensing systems. To control the transport of multiple liquids without any external equipment, we utilize capillary attraction force for filling and surface tension for stopping liquid flow. As a driving force, hydraulic pressure caused by the elastic deformation of a liquid reservoir transfers liquid stopped at passive valves. The proposed LOC successfully demonstrates a reliable sequential liquid transfer within the reaction channel. To highlight its feasibility as a portable diagnostic system, we performed the electrochemical immunoassay measuring antibody concentrations within the fabricated LOC. As a test biorecognition reaction, the anti-dinitrophenyl (DNP) antibody with an enzymatic catalysis was selected as the target analyte. The amplified signals obtained from this experiment indicated a high selectivity of the immunosensing LOC.