A velocimeter/nephelometer for measuring the three-dimensional velocity and/or size and/or shape of a particle. A set of laser interferometers and a set of photodiode detectors are arranged on a two-dimensional platform. Each laser interferometer produces a laser beam, with the beams intersecting within an inner area of the platform. Two of the laser interferometers produce like-oriented fringe patterns with an angular separation between the propagation direction of their beams of ninety degrees. A third of the laser interferometers produces a beam with the fringe pattern oriented orthogonal to the fringe patterns of the other two laser interferometers. Each detector is positioned and filtered to detect light from an associated laser interferometer, the light having been scattered by a particle as the particle passes through a volume of observation.

An optofluidic device includes: a housing having an inlet port coupled to an inlet side and an outlet port coupled to an outlet side; and a microlens disposed within the housing between the inlet side and the outlet side. A fluid having a plurality of particles flows from the inlet side through the microlens to the outlet side. The optofluidic device further includes a light source configured to emit a light beam in a direction opposite flow direction of the fluid, the light beam defining an optical axis that is perpendicular to the microlens.

Examples disclosed herein relate to system and method for detecting the size of a particle in a fluid. The system includes a conduit for transporting a fluid and a sample area. Some of the fluid passes through the sample area. A first imaging device has an optical lens and a digital detector. A laser source emits a first laser beam. The digital detector generates a metric of an initial intensity of a scattered light that passes through the optical lens. The scattered light is scattered from particles passing through the sample area, and includes light from the first laser beam, which passes through the sample area. A controller outputs a corrected particle intensity based upon a comparison of the initial intensity to data representative of intensity of a focused and defocused particle. The corrected particle intensity generates a corrected metric corresponding to an actual size of the particles.

Systems for detecting, capturing, and/or measuring nanoparticles. The system may include a first vacuum chamber, where nanoparticles are formed inside a first cavity of the first vacuum. The system may also include a second vacuum chamber in fluid communication with the first vacuum chamber, a particle collection component positioned within a second cavity of the second vacuum chamber, and a particle collection medium disposed over the particle collection component. Additionally, the system may include a particle counter in fluid communication with the second vacuum chamber, and a control system operably coupled to the component. The control system may be configured to aerosolize the nanoparticles by adjusting a temperature of the component to a first temperature that establishes the medium in the solid phase, and adjusting the temperature of the component to a second temperature to transition the medium from the solid phase to a gaseous phase.

In one example in accordance with the present disclosure, am ejection system is described. The ejection system includes a fluid feed slot to supply fluid to a number of fluid ejection channels where each fluid ejection channel is a recirculating channel. Each fluid ejection channel includes a sensor to detect, in the fluid, a target particle to be ejected and a fluid ejector to eject the target particle from the fluid ejection channel. The ejection system also includes a controller to selectively activate the fluid ejector when the target particle presence is detected. Non-target particles are returned to the fluid feed slot past the fluid ejector.

An object identification method capable of quickly and accurately identifying a virus or the like is provided. An object identification method according to an aspect of the present disclosure includes feeding an object dispersed in a solvent to a micro-channel, and applying an AC (Alternating Current) voltage to a measurement electrode provided at the micro-channel and measuring an AC characteristic of the object when the object passes through the micro-channel. Then, a combined impedance and a phase are determined by using the measured AC characteristic, and the object is identified by using the determined combined impedance and the phase.

In one example in accordance with the present disclosure, a system is described. The system includes a fluidic die to advance across an ejection path relative to a substrate. The fluidic die includes a channel to contain a portion of a sample fluid, a sensor to detect passage of a particle within the sample fluid into the channel, and an ejection device. The ejection device is to eject the particle. The system also includes a controller. The controller identifies discrete locations along the ejection path as waste sites as the fluidic die advances along the ejection path. This is done by 1) classifying the particle as a target particle or a non-target particle, 2) upon identification of a target particle, ejecting the target particle to a target site of the substrate, and 3) upon identification of a non-target particle, ejecting the non-target particle to a waste site.

Systems and methods for flowing particles, such as biological entities, in a fluidic channel(s) are generally provided. In some cases, the systems described herein are designed such that a single particle may be isolated from a plurality of particles and flowed into a fluidic channel (e.g., a microfluidic channel) and/or collected e.g., on fluidically isolated surfaces. For example, the single particle may be present in a plurality of particles of relatively high density and the single particle is flowed into a fluidic channel, such that it is separated from the plurality of particles. The particles may be spaced within a fluidic channel so that individual particles may be measured/observed over time. In certain embodiments, the particle may be a biological entity. Such article and methods may be useful, for example, for isolating single cells into individual wells of multi-well cell culture dishes (e.g., for single-cell analysis).

This technology relates in part to optical methods for analyzing particles, including nanoparticles, thereby determining their presence, identity, origin, size and/or number in a sample of interest.

Embodiments of apparatus and methods for counting cells in a liquid sample are provided herein. In some embodiments, an apparatus for counting cells in a liquid sample includes: a flow-splitting chamber fluidly coupled to a collection chamber; an input tube configured to deliver a liquid sample to the flow-splitting chamber; a spaced apart array of posts along a flow path configured to redirect the liquid sample into a plurality of streams; a plurality of sensing zones corresponding to the plurality of streams; and a plurality of sensing electrodes, wherein each sensing electrode is disposed in a corresponding sensing zone of the plurality of sensing zones and configured to detect a change in electrical impedance as the liquid sample flows through the plurality of sensing zones.