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This paper describes a revolutionary micromachined accelerometer which is simple, reliable, and inexpensive to make. The operating principle of this accelerometer is based on free-convection heat transfer of a tiny hot air bubble in an enclosed chamber. An experimental device has demonstrated a 0.6 milli-g sensitivity which can theoretically be extended to sub-micro-g level.

Micro fuel cell systems have elicited significant interest due to their promise for instantly rechargeable, longer duration and portable power. Most micro fuel cell systems are either built as miniaturized plate-and-frame or silicon-based microelectromechanical systems (MEMS). Plate-and-frame systems are difficult to fabricate smaller than 20 cm3. Existing micro fuel cell designs cannot meet the cost, scale and power requirements of some portable power markets. Traditional MEMS scaling advantages do not apply to fuel cells because the minimum area for the fuel cell is fixed by the catalyst area required for a given power output, and minimum volume set by mass transport limitations. We have developed a new hybrid technique that borrows from both micro and macro machining techniques to create fuel cells in the 1–20 cm3 range, suitable for cell phones, PDAs and smaller devices.

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With the development of microfluidic systems, there is a growing interest in micro scale laminar flow mixing. In this work, the fluid rotating angle and mixing efficiency in a micromixer with patterned grooves are studied as a function of the dimensions of the microstructure by numerical simulation. We found that mixing efficiency does not always increase with higher fluid stream rotation in the microchannel. High groove aspect ratios are not advantageous to fluid rotation. Experiments on mixture of two fluids were done on a micromixer fabricated in PDMS by replica molding. An 85% mixing efficiency was obtained in a 30mm long mixing channel with two dyed liquids.