title: Convergent, self-encoded bead sensor arrays in the design of an artificial nose.
abstract: We report a new approach to designing an artificial nose based on high-density optical arrays that directly incorporate a number of structural and operational features of the olfactory system. The arrays are comprised of thousands of microsphere (bead) sensors, each belonging to a discrete class, randomly dispersed across the face of an etched optical imaging fiber. Beads are recognized and classified after array assembly by their unique, "self-encoded" response pattern to a selected vapor pulse. The high degree of redundancy built into the array parallels that found in nature and affords new opportunities for chemical-sensor signal amplification. Since each bead is independently addressable through its own light channel, it is possible to combine responses from same-type beads randomly distributed throughout the array in a manner reminiscent of the sensory-neuron convergence observed in the mammalian olfactory system. Signal-to-noise improvements of approximately n1/2 have been achieved using this method.
authors.affiliation: Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Dickinson
authors.forename: K L
authors.initials: KL
authors.lastname: Michael
authors.forename: J S
authors.initials: JS
authors.lastname: Kauer
authors.forename: D R
authors.initials: DR
authors.lastname: Walt
mesh_terms: D001187:Artificial Organs; D015374:Biosensing Techniques; D005336:Fiber Optic Technology; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008863:Microspheres; D008954:Models, Biological; D009666:Nose / Q000502:physiology; D009812:Odorants / Q000032:analysis*; D009830:Olfactory Bulb / Q000502:physiology