Molded arrays of microcavities and channels in polymer structures: Ultraviolet emitting microplasma sources for biophotonics

Microplasma arrays and channels fabricated on plastic substrates by replica molding are well suited for biomolecule detection in liquid flow streams. Arrays of orthogonally oriented linear channels with cross-sectional areas of 100 × 100 μm² have been operated in Ar/3% N₂ gas mixtures at atmospheric pressure. Similar experiments with arrays of parallel linear channels having cross-sectional areas of 200 × 100 μm² and lengths of 6 cm have also been conducted. Spatially uniform emission in the near ultraviolet (λ ∼300-400 nm) from the microcavity plasma sources and the photoluminescence of organic molecules in solution in adjoining channels have been observed.