Abstract: A biological/chemical detector is disclosed that is capable of manipulating liquids, such as reagent droplets, without relying on microchannels. In a first embodiment, fluid flow is passed through the detector, thus causing particles wholly or partially containing an illustrative chemical compound or biological species to be collected on the tips of nanostructures in the detector. A droplet of liquid is moved across the tips of the nanostructures, thus absorbing the particles into the liquid. The droplet is caused to penetrate the nanostructures in a desired location, thus causing the chemical compound or biological species in said liquid droplet to come into contact with, for example, a reagent. In another embodiment, a fluid flow is passed through the nanostructured surfaces of the detector such that the chemical compound and/or biological species are deposited between the nanoposts of a desired pixel.

Abstract: A method for determining the shape and size of particles and their constituent elements is disclosed. Particle ions are accelerated through a mass spectrometer useful in identifying the source particle of the resulting ions. By measuring the time-varying intensity of the identified ions as they strike a detector, a plot of the intensity of the ions over time is obtained for each ionized particle. The size of each ionized particle is determined by measuring a time span corresponding to the width of the peak of this plot. If the detector is a phosphor detector, the shape of the particle may be determined by using a high-speed camera to capture cross-section images of the ion-induced light pattern at closely-spaced successive moments in time. Alternatively, the intensity of ions striking the detector along at least one lateral dimension may be detected.