Optical trapping, manipulation, and sorting of cells and colloids in microfluidic systems with diode laser bars

We demonstrate a new technique for trapping, sorting, and manipulating cells and micrometer-sized particles within microfluidic systems, using a diode laser bar. This approach overcomes the scaling limitations of conventional scanned laser traps, while avoiding the computational and optical complexity inherent to holographic optical trapping schemes. The diode laser bar enables us to control a large trapping zone, 1 mum by 100 mum, without the necessity of scanning or altering the phase of the beam. (C) 2004 Optical Society of America.