title: Microfabricated high-throughput electronic particle detector.
abstract: We describe the design, fabrication, and use of a radio frequency reflectometer integrated with a microfluidic system, applied to the very high-throughput measurement of micron-scale particles, passing in a microfluidic channel through the sensor region. The device operates as a microfabricated Coulter counter [U.S. Patent No. 2656508 (1953)], similar to a design we have described previously, but here with significantly improved electrode geometry as well as including electronic tuning of the reflectometer; the two improvements yielding an improvement by more than a factor of 10 in the signal to noise and in the diametric discrimination of single particles. We demonstrate the high-throughput discrimination of polystyrene beads with diameters in the 4-10 microm range, achieving diametric resolutions comparable to the intrinsic spread of diameters in the bead distribution, at rates in excess of 15 x 10(6) beads/h.
authors.affiliation: Department of Physics, University of California at Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Wood
authors.forename: M V
authors.initials: MV
authors.lastname: Requa
authors.forename: A N
authors.initials: AN
authors.lastname: Cleland
mesh_terms: D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation* / Q000379:methods; D008839:Microelectrodes; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization; D053758:Nanoparticles / Q000032:analysis*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity