Customization of poly(dimethylsiloxane) stamps by micromachining using a femtosecond-pulsed laser

A femtosecond-pulsed Ti:sapphire laser is used to generate surface features in slabs of poly(dimethylsiloxane) with minimum dimensions of 1 mum-smaller than those available by rapid-prototyping techniques using transparency masks. The fabrication of magnetic field concentrators and the addition of custom features to a generic microfluidic channel (see Figure) demonstrate the utility of the technique.