Integrated bio/chemical microsystems employing optical detection: A cytometer

The fabrication and characterisation of a silicon chip containing a miniature flow cytometer which is integrated with microcapillary and optical fiber connectors, as well as, an array of optical waveguide coupled photodiodes for detecting scattered light is discussed. Measurements of the properties of the photodiodes and optical waveguides have been performed in order to characterize these these structures. The photdiodes have responsivities of approximately 0.5 A/W over the visual spectrum while the waveguides exhibit optical losses of 0.5 dB/cm or less. Preliminary measurements concerning the effectiveness of the connectors, transport in the microchannels, and light scattering of beads and cells irradiated by a beam of laser light while moving through the microchannel are also discussed.