Spectral discrimination of dynamical chemical signals with fourier microfluidics

We report the design and fabrication of microfluidic Fourier band-pass filters which are capable of separating dynamic chemical signals based on differences in their frequency-domain spectral characteristics. The filters were prepared using a double-layer PDMS stamp process with on-chip pneumatic valves. All fluidic channels were formed using silicon wafer micro-molds with a cross section of 6 mum times 25 mum. The measured transfer function shows clear peaks at discrete frequencies of 0.17 Hz, 0.34 Hz, and 0.51 Hz, when analyte was injected at 15 psi consistent with the result of the computer simulations.