Dynamic chemical signal are pervasive in biology. In spite of their relevance, there are no well established techniques for analysis and separation of time-dependent signals. Conventional chemical analysis techniques such as electrophoresis and liquid chromatography can only be used for the analysis of finite, discrete and time invariant samples; hence many samples must be collected to determine the dynamic nature of a sample. As a rapidly developing scientific filed, microfluidics, which benefit tremendously from using PDMS as a ubiquitous platform, provides possible solutions for the analysis and measuring of dynamic chemical signal. This book describes our strategies and efforts to develop novel microfluidic techniques enabling the analysis of dynamic chemical signals based on their Fourier, frequency-domain characteristics rather than their chemical nature. The new techniques for chemical signal analysis introduced in this book should be interesting to professionals in chemical analysis, or anyone else who is interested in utilizing microfuidic methods for biomedical system analysis.