Detection of trace arsenic in drinking water: challenges and opportunities for microfluidics

Conception of a micro total analytical system (μTAS), capable of sample preparation, sample analysis, and signal acquisition, for portable trace arsenic detection.

Measurement of nitrogen monoxide levels in gas flows with a micro total analytical system based on LTCC

The measurement of nitrogen monoxide (NO) concentration levels is a vital aspect of environmental analysis and the so called CHNS analysis. The chemiluminescent reaction with ozone in the gas phase is a well-established method for the measurement of atmospheric concentration levels in the range from 4 ppb up to 100 ppm. In this contribution we present the design of a so called micro total analytical system (μTAS) for NO measurements designed in ceramic. Low temperature co-fired ceramics (LTCC) have proven to be the ideal technology, since they offer high chemical and thermal stability as well as high degree of freedom of design. The article gives an overview of the design process with emphasis on manufacture of the components and technological challenges regarding life-time.

Coupled Electrostatic-Structures-Fluidic Analysis of a Nozzle/Diffuser Diaphragm Micropump

Micropump is the key component in the micro total analytical system. The major technical impediment in improving the performance of this micro-device lies in the lack of understanding the physical phenomena and their interactions of electric, mechanical, and fluidic fields for performing their intended functions. Because of the complexity of the micropump, the full coupled numerical analysis is extremely needed. This paper presents for the results of such fully coupled simulations. CFDRC® was used for the transient analysis of an electrostatically actuated micropump. The results show that the dynamic characteristics of fluid in the micropump and the vibration of flexible diaphragm are highly interactive each other. The flow rectification of the nozzle/diffuser will work only after the pressure difference between the two ends of valve have reached at a critical value. In the pump chamber, the fluidic press distribution almost independent of the space variation. Due to the increasing demands for accuracy, the nonlinear features of viscous loss of the fluid can no longer be neglected or simplified, but have to be taken into account in detail.