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Thermal properties and power consumption of a micro heater used in micro polymerase chain reaction (uPCR) chip was analyzed utilizing Finite Element Analysis (FEA), and a low power and high efficiency micro heater was designed. By using borosilicate-glass as the substrate instead of silicon, the power consumption of the uPCR chip reduced 80%. To overcome the high thermal insulation of the borosilicate-glass substrate, water forced cooling system based on micro flow channels was designed to speed up the uPCR cycling. 3D thermal and fluidic models of the uPCR chip with both micro heaters fabricated on silicon and borosilicate-glass were built to analyze their properties. The depth of the micro flow channel was optimized. Experimental results revealed that the cooling rate reached 13.8deg/s with the 100um-deep micro flow channel.

RF MEMS (Radio Frequency Microelectromechanical System) has seen an amazing growth in the past 20 years. It has immense commercial and defense potential due to its low loss, low power consumption and superior RF performances. In this article, RF MEMS and its applications are reviewed. Special emphasis is on the RF MEMS switches and MEMS phase shifters investigated in IMETU (Institute of Microelectronics of Tsinghua University). A variety of RF MEMS switches with different configurations are introduced. The MEMS switch present unique properties for the application in future miniaturized antenna and radar system. The prototype illustrates the RF MEMS switch as a fundamental structure in signal path control, structural optimization, and match circuits is very promising to be used in future reconfigurable radar and antenna system, which will address to the application not only in the mobile terminal but also the high end wireless sensor network.

A uPCR system and its Electrochemical (EC) detection circuits are presented. The system consists of a uPCR chip packaged on a printed circuit board (PCB), peripheral signal read-out circuits and control circuits. The uPCR chip is realized with MEMS-technology contains an array of 3x4 reaction chamber. A microcontroller unit (MCU) is used in the control system to monitor the reaction procedure (PCR cycling) and handle the signal measurement. A Logarithmic Current Mode Amplifier (LGCMA) is proposed and realized as the EC signal amplification and I-V conversion. The test results shows that the obtained chip presents good Logarithmic DC characteristics within a current change from 1nA to 1uA and the corresponding output is from -4.43V to -3.52V. Thermal cycling experiment was carried to verified the control system, The results show that the variation of temperature is 0.1degC at the stable state.

With fast development of mobile communication technology, the increasingly complex communicating environment and the crowded spectrum have raised stringent requirements on the RF front-end performance. In this paper, the influence of human body on the communication performance is analyzed. In particular, it is shown that the antenna input impedance faces huge variation in the frame of body-centric devices. Consequently, automatic impedance matching appears to be crucial to improve the performance withstand the inconstant environment. The investigation of key tunable components of RF MEMS is therefore presented. A variable capacitor with symmetric balanced structure is designed to achieve a large capacitance tuning ratio and a remarkable linearity of the C-V response. The proposed RF MEMS variable capacitor was modeled and simulated. The results show a linearity factor of 99.82% in C-V response and a large tuning ratio of 480% in a low actuation voltage range from 0V to 16.3V.

A μPCR system and its Electrochemical (EC) detection circuits are presented. The system consists of a μPCR chip packaged on a printed circuit board (PCB), peripheral signal read-out circuits and control circuits. The μPCR chip is realized with MEMS-technology contains an array of 3×4 reaction chamber. A microcontroller unit (MCU) is used in the control system to monitor the reaction procedure (PCR cycling) and handle the signal measurement. A Logarithmic Current Mode Amplifier (LGCMA) is proposed and realized as the EC signal amplification and I-V conversion. The test results shows that the obtained chip presents good Logarithmic DC characteristics within a current change from 1nA to 1μA and the corresponding output is from -4.43V to -3.52V. Thermal cycling experiment was carried to verified the control system, The results show that the variation of temperature is 0.1°C at the stable state.