We report the development of a micromachined magnetic-bar micromixer for microscale fluid mixing in biological laboratory-on-a-chip applications. The mixer design is inspired by large scale magnetic bar mixers. A rotating magnetic field causes a single magnetic bar or an array of them to rotate rapidly within a fluid environment. A fabrication process of the magnetic bar mixer is developed. Res...

Rotating spiral waves without phase singularity are found to arise in a certain class of three-component reaction-diffusion systems of biological relevance. It is argued that this phenomenon is universal when some chemical components involved are diffusion-free. Some more detailed mathematical and numerical analyses are carried out on a complex GinzburgLandau equation with non-local coupling to...