2008.8
About Instruments Today No. 165
CMOS MEMS Sensors
CMOS MEMS Accelerometer [ 下載 PDF ]
Weileun Fang, Chih-Ming Sun, Chuanwei Wang, Ming-Han Tsai
Presently, the CMOS MEMS and its related technologies become more and more popular. Many commercialized products have been realized using the CMOS MEMS technology. There are even more on-going researches involving in the CMOS MEMS related fields. In this article, the authors would like to introduce the design and fabrication of the CMOS MEMS accelerometers. In application, various accelerometers implemented by the authors research group in the Micro-Device Lab., National Tsing Hua University are reported. These accelerometers are fabricated using the TSMC 0.35 µm standard CMOS process plus the post-CMOS process developed by authors.
CMOS MEMS and Its Applications in Sensors [ 下載 PDF ]
Jen-Yi Chen
CMOS integrated sensors possess the advantages of size miniaturization, improved sensitivity and electrical routing capability. Since the emerging applications rising, the requirements for micro sensors are diverse in size, performance, cost and so on. This article discusses the common used sensing mechanisms benefited by the integration with CMOS technology. Various fabrication approaches are introduced to realize the CMOS integrated sensors. Finally, three existed examples including hot wire anemometer, capacitive accelerometer and condenser microphone are used to demonstrate the implementation of CMOS micro sensors.
The CMOS MEMS Design Platform for Heterogeneous Integration [ 下載 PDF ]
Ying-Zong Juang
To integrate the sensor function is the future trend of 3C products. The CMOS MEMS technology platform is convenient to be adopted for the integration of micro-sensing system. The design kits including the design rule file, process description file, material parameters, and reference design are important to make a powerful platform for the implementation of heterogeneous circuit and system.
A Platform of CMOS MEMS Microcantilever for Chemical and Biochemical Detection [ 下載 PDF ]
Kuan Shu, Long-Shen Huang
Over the past few years, an increasingly number of studies have been conducted on using the microcantilevers as transducers in biochemical-sensing systems. With the bottom-up technology in chemical surface treatment and biomolecular functionality and the top-down microfabrication on physical devices, the biofilm-induced CMOS compatible microcantilever establishes a platform in real-time, label-free, and quantitative analysis which facilitates the discovery of new drugs, monitor of the environmental, biotechnological methods, and materials for therapeutics and diagnostics. In this article, we will introduce several important research groups in the field of Chemical and Biochemical Detection. In summary, the anomechanics-based microcantilever platform exhibits its broad applicability, effectiveness, high microelectronics integration, promising wireless sensor networks as well. Therefore, a flexible, efficient, and integrated design environment should be constructed for MEMS industry to speed up the design flow, reduce research cost and improve the product reliability.
CMOS MEMS Gas Sensors [ 下載 PDF ]
Ching-Liang Dai, Mao-Chen Liu
Various industrial applications and environmental monitoring require gas sensors so that they develop rapidly. In this paper, the development and principle of gas sensors will be introduced, and the CMOS MEMS humidity sensor and carbon monoxide (CO) sensor developed by my research term will be presented. Both of the gas sensors, which are resistive type, consist of a sensing film, a sensing resistor, a micro heater and readout circuits. The sensing film that is prepared by sol-gel method is coated on the sensing resistor. When the sensing film absorbs or desorbs sensing gas, the sensing resistor changes in resistance. The readout circuits are employed to convert the resistance variation of the sensing resistor into the output voltage. Experiments show that the humidity sensor has a sensitivity of 4.5 mV/% RH at 60 °C and the CO sensor has a sensitivity of 1 mV/ppm.
Tabletop High-Repetition-Rate X-Ray Laser [ 下載 PDF ]
Ming-Chang Chou, Ping-Hsun Lin, Hsu-Hsin Chu, Jiunn-Yuan Lin, Jyhpyng Wang, Szu-yuan Chen
Many breakthroughs have been made in the development of high-brightness, high-repetition-rate, tabletop X-ray lasers recently. Because of their short wavelength and femtoseond-scale pulse duration, such X-ray lasers are of great potential for frontier research and application in various scientific fields. This article summarizes the accomplishments we have made on the development of optical-field-ionization collisional-excitation X-ray lasers, through which the readers can learn the basics for the general setup configuration, design considerations, and output characteristics of X-ray lasers.
Attosecond Pulse Train Generation by Coherent Molecular Modulation [ 下載 PDF ]
Wei-Jan Chen, A. H. Kung, Chao-Kuei Lee, Ci-Ling Pan, Ru-Pin Chao
We induce hydrogen molecules to undergo coherent vibrational motion with two driving lasers. This coherent motion modulates the driving laser frequency and generates high-order Raman sidebands. The spectral spread of these Raman sidebands reaches 70,000 cm−1. By synthesizing pulses using these sidebands we can get pulse trains in the attosecond regime. Here we describe the synthesis of periodic waveforms consisting of a train of pulses that are 0.83 cycles long and have an electric field pulse width of 0.44 fs using 7 Raman sidebands generated by molecular modulation in H2.
Applications of Nanoparticle Matrices for Surface-Assisted Laser Desorption/Ionization Mass Spectrometry and Surface-Enhanced Raman Spectroscopy [ 下載 PDF ]
Ming-Feng Huang, Kun-Hong Lee, Kun-Hong Lee, Cheng-Kang Chiang, Huan-Tsung Chang
This article briefly reviews the use of nanoparticles as matrices for the determination of small molecules using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) and as surface-enhanced Raman spectroscopy (SERS)-active substrates. It is easy to prepare bioconjugated nanoparticles that have great surface area for selective recognition of analytes of interest. In addition, nanoparticles having high molar absorptivity in the UVVis region are effective inorganic matrixes for the analysis of small molecules by SALDI-MS. Recently, attention has turned toward the development of SERS-active nanoparticle substrates for use as an ultrasensitive platform for the detection of biological molecules.
Charged Solute Ions Motion Phenomenon in Cross Channel of Capillary Zone Electrophoresis Chip [ 下載 PDF ]
Ming-Ying Hsu, Chen-I Hung
Traditional numerical schemes use the concentration diffusion equation to simulate the solute concentration distribution in CZE (capillary zone electrophoresis) systems. However, although this equation adequately describes the diffusion of a solute liquid in such systems, it cannot describe the different motions of the differently charged solute ions. Therefore, this study employs a particle model to simulate solute ionic migration. Using the Navier- Stokes equation and the PIC (particle in caell) method, this study examines the absolute mobility of negatively and positively charged ions in non-aqueous solvents in a CZE system. The results show that the zeta potential on the channel wall affects the migration of the positive and negative ions in the electrical double layer (EDL) in different ways. Specifically, the positive ions accumulate at the channel wall, while the negative ions are pushed out of the EDL. Furthermore, it is shown that the positive ions migrate more rapidly than the negative ions in the injection process.
