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Monitoring blood coagulation is an important issue in the surgeries and the treatment of cardiovascular diseases. In this work, we reported a novel strategy for the blood coagulation monitoring based on a micro-electromechanical film bulk acoustic resonator. The resonator was excited by a lateral electric field and operated under the shear mode with a frequency of 1.9 GHz. According to the apparent step-ladder curves of the frequency response to the change of blood viscoelasticity, the coagulation time (prothrombin time) and the coagulation kinetics were measured with the sample consumption of only 1 μl. The procoagulant activity of thromboplastin and the anticoagulant effect of heparin on the blood coagulation process were illustrated exemplarily. The measured prothrombin times showed a good linear correlation with R 2 =0.99969 and a consistency with the coefficient of variation less than 5% compared with the commercial coagulometer. The proposed film bulk acoustic sensor, which has the advantages of small size, light weight, low cost, simple operation and little sample consumption, is a promising device for miniaturized, online and automated analytical system for routine diagnostics of hemostatic status and personal health monitoring. [ABSTRACT FROM AUTHOR]

There is an expanding interface between electronic engineering and neurosurgery. Rapid advances in microelectronics and materials science, driven largely by consumer demand, are inspiring and accelerating development of a new generation of diagnostic, therapeutic, and prosthetic devices for implantation in the nervous system. This paper reviews some of the basic science underpinning their development and outlines some opportunities and challenges for their use in neurosurgery. [ABSTRACT FROM AUTHOR]

Abstract: Dual pulse actuation voltage waveforms that are capable of mitigating micro-electromechanical system (MEMS) switch bouncing are presented. The displacement and velocity of the MEMS switch membrane actuated using these waveforms are then simulated and compared. To eliminate bouncing, the velocity of the membrane should ideally be zero just before contact is made. Otherwise the large momentum from high velocity impact will bounce the membrane back, extending the switching time and bringing about wear and tear to the contact surfaces. The effect of MEMS switch parameter variations on the bouncing membrane is then studied for switches with different gap widths. The impact of the variation in the voltage waveform is also investigated in this paper. The exponentially saturating dual-pulse actuation waveform has shown great robustness against both switch and voltage waveform parameter variations. The waveform also exhibited the fastest switching time for a wider range of parameters variations. Practical experiments were carried out on TeraVicta TT712-68CSP MEMS switch to corroborate the findings. [Copyright &y& Elsevier]

Abstract: In this work, we present a 4-cell air-breathing micro direct methanol fuel cell (μDMFC) stack featured with novel n-inlet and n-outlet (NINO) anode flow fields. Compared with the conventional parallel flow field, the NINO flow field with micro structures improves the methanol solution transport efficiency and facilitates the exclusion of CO2 gas bubbles accumulated in flow channels. The μDMFC stack patterned with novel NINO flow field is fabricated using silicon-based micro electromechanical system (MEMS) technologies. The polydimethylsiloxane (PDMS) distributors are used not only for the stack packaging but also for the uniform distribution of methanol solution through the connected double-side patterns. Experimental results reveal that the NINO flow fields exhibit higher peak power density than that of the conventional flow field. The NINO structures with different patterns have significant influences not only on the momentum transfer but also on the cell performance. The maximum power output of the μDMFC stack can yield about 80mW at room temperature, which is significative for portable applications. [Copyright &y& Elsevier]

Abstract: These last 10 years, smaller, less expensive, and higher performance sensors are required for gas sensing applications. To date no true detection principle has been recognized as the best candidate for such application. Microsytems or Micro/Nano ElectroMechanical Systems (M/NEMS) used as gravimetric detectors are among the probable candidates. The technology can indeed be manufactured en masse and can provide multi-gas analysing platform. In this paper, we present a comprehensive overview of micro/nano sensors based on the gravimetric effect to detect an absorbed gas on top of their surfaces. The paper provides a comparison between different electromechanical devices (Bulk Acoustic Wave, Surface Acoustic Wave, Capacitive Micro-machined Ultrasonic Transducer, Micro/Nano cantilevers) with an introduction to gas adsorption mechanisms, material selection, detection principles and design guidance useful to researchers or engineers. [Copyright &y& Elsevier]

In order to understand the loss mechanism of mechanical oscillators in micro-electromechanical systems, we have studied the temperature dependence of the quality factor Q of a high Q silicon mechanical oscillator from 0.4 to 300 K. At temperatures above 70 K, the energy loss is principally caused by thermoelastic effect in the flexural components of the modes. Below 50 K, we find the improvements in vibration isolation guided by the finite element method which do not significantly improve its Q. This indicates that some intrinsic loss mechanism may still be important even at low temperatures. [Copyright &y& Elsevier]

• Influencing parameters of the flame optimization schemes are summarized. • Influence parameters of the micro-thermal photoelectric system are analyzed. • Influence parameters of the thermoelectric conversion efficiency are investigated. • Technical limitations and development of the micro power equipment are summarized. Hydrocarbon fuel and hydrogen are used as fuels for micro power equipment to replace traditional batteries and provide energy for micro-electromechanical systems, which has become a hot research direction. However, due to the reduction in the size of micro power equipment, not only the flame in the micro combustor is affected, but the overall energy conversion efficiency of micro power equipment is also affected by the size effect. Therefore, it is significance to analyze the energy loss and design optimization methods pertinently from the point of energy conversion. In the past ten years, many researchers have done research about the direction, which has been reviewed in this article. For the flame optimization, the influencing parameters of optimization methods such as exhaust gas recirculation, cavity combustor, bluff body combustor, porous media combustion, and hydrocarbon fuels mixed with hydrogen are summarized. For the micro-thermal photoelectric system, the influence parameters of combustion efficiency, radiant efficiency, spectral efficiency, view factor efficiency and photovoltaic cell efficiency are analyzed. In the micro-thermoelectric system, the influence parameters of combustion efficiency, heat conduction efficiency and thermoelectric conversion efficiency are analyzed. For the micro internal combustion engine, the influencing parameters of combustion efficiency and conversion efficiency are analyzed. Finally, the technical limitations and development of each micro power equipment are summarized in this article. [ABSTRACT FROM AUTHOR]