Abstract: An opposed migration classifier classifies particles suspended in a sample fluid that are passed through a classification channel defined by two permeable walls. Sample flow distribution input and output channels are located asymmetrically with respect to a center of the classification channel such that trajectories of the one or more particles in the sample fluid deviate from constant voltage operation trajectories. A cross-flow fluid enters the classification channel through a permeable wall and exits through the other permeable wall. An imposed field, created by a time varying filed imposed in a direction normal to the permeable walls, causes the particles to migrate in a direction opposite to that of the cross-flow fluid, such that the particles travel between the permeable walls. The particles in the sample are classified based on their mobility. The sample fluid enters and exists through or within a threshold distance of the permeable walls.

Abstract: The present disclosure describes a compact and lightweight, radial-flow DMA designed to operate at low aerosol and sheath flowrates (on the order of 0.3 L/min aerosol flow, and 0.6-1.2 L/min sheath flow) and so as to classify aerosols including particles having sizes in the 10-500 nm range. Thus, the DMA is capable of operating at relatively low resolution (RND=2-4) to minimize both instrument volume and pumping/power requirements, while enabling size distribution measurement with the precision required for desired applications.

Abstract: An opposed migration classifier classifies particles suspended in a sample fluid that are passed through a classification channel defined by two permeable walls. Sample flow distribution input and output channels are located asymmetrically with respect to a center of the classification channel such that trajectories of the one or more particles in the sample fluid deviate from constant voltage operation trajectories. A cross-flow fluid enters the classification channel through a permeable wall and exits through the other permeable wall. An imposed field, created by a time varying filed imposed in a direction normal to the permeable walls, causes the particles to migrate in a direction opposite to that of the cross-flow fluid, such that the particles travel between the permeable walls. The particles in the sample are classified based on their mobility. The sample fluid enters and exists through or within a threshold distance of the permeable walls.

Abstract: The present disclosure describes a compact and lightweight, radial-flow DMA designed to operate at low aerosol and sheath flowrates (on the order of 0.3 L/min aerosol flow, and 0.6-1.2 L/min sheath flow) and so as to classify aerosols including particles having sizes in the 10-500 nm range. Thus, the DMA is capable of operating at relatively low resolution (RND=2-4) to minimize both instrument volume and pumping/power requirements, while enabling size distribution measurement with the precision required for desired applications.

Abstract: A continuous flow mobility classifier provide the ability to perform two-dimensional separation in mass spectrometry. An ionization system is used to ionize a sample. A differential mobility analyzer (DMA) (e.g., a nano-radial DMA) is coupled to the ionization system and to a mass spectrometer. The nano-RDMA is configured to separate the ionized sample by mobility for subsequent mass analysis by the mass spectrometer.

Abstract: A method is provided for changing a property of a sample. A sample, comprising particles suspended within a sample fluid, is introduced into a channel which comprises two walls that are permeable to a flow of fluid. A cross-flow is introduced at a predetermined temperature and of a predetermined chemical composition into the channel through a wall. This cross-flow flows at a first velocity and exits in a first direction through the other wall. An imposed field is applied on the particles in a second direction counter to the first direction of the cross-flow. The imposed field causes the particles to migrate at a second velocity opposite and/or equal to the first velocity of the cross-flow. Particles that are approximately balanced by the first and second velocities travel through the channel and are discharged in a fluid of predetermined chemical composition and at the predetermined temperature of the cross-flow.

Abstract: Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.

Abstract: A radial opposed migration classifier is provided for separating particles in a sample, introducing and removing the particles into and out of the classifier at the same potential. A sample passes through a classification channel having two circular walls. The sample is introduced and exits the classifier through the same plane as the first wall, which is at a different potential from the second wall. A cross-flow fluid enters the classification channel through one of the walls. The cross-flow fluid flows at a first velocity and exits in a first direction through the other wall. An imposed field is applied on the particles in a second direction counter to the first direction of the cross-flow. This causes the particles of a desired size and/or charge to migrate at a second velocity opposite and/or equal to a first velocity of the cross-flow. The particles that travel through the channel are discharged.

Abstract: Systems and methods for concentrating solar energy without tracking the sun are provided. In one embodiment, the invention relates to a solar collector assembly for collecting and concentrating light for solar cell assemblies, the collector assembly including an array of solar collectors, each including a funnel shaped collector including a side wall defining a tapered opening having a base aperture and an upper aperture, the side wall including an outer surface, and a solar cell assembly positioned at the base aperture, where the outer surface is coated with a material that substantially reflects light, where the upper aperture is wider than the base aperture, where the funnel shaped collector is configured to substantially confine light, incident via the upper aperture, within the funnel shaped collector until the light exits proximate the base aperture, and where the solar cell assembly is configured to capture light exiting the base aperture.

Abstract: An optoelectronic swept-frequency semiconductor laser coupled to a microfabricated optical biomolecular sensor with integrated resonator and waveguide and methods related thereto are described. Biomolecular sensors with optical resonator microfabricated with integrated waveguide operation can be in a microfluidic flow cell.

Abstract: Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating. The coating deformation and/or a change of one or more optical properties of the optical energy circulating within the micro-cavity are used to detect the presence of the gas or vapor or molecules or particulates thereof.

Abstract: An optoelectronic swept-frequency semiconductor laser coupled to a microfabricated optical biomolecular sensor with integrated resonator and waveguide and methods related thereto are described. Biomolecular sensors with optical resonator microfabricated with integrated waveguide operation can be in a microfluidic flow cell.

Abstract: Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating.

Abstract: Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.

Abstract: Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating. The coating deformation and/or a change of one or more optical properties of the optical energy circulating within the micro-cavity are used to detect the presence of the gas or vapor or molecules or particulates thereof.

Abstract: Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.

Abstract: A continuous flow mobility classifier provide the ability to perform two-dimensional separation in mass spectrometry. An ionization system is used to ionize a sample. A differential mobility analyzer (DMA) (e.g., a nano-radial DMA) is coupled to the ionization system and to a mass spectrometer. The nano-RDMA is configured to separate the ionized sample by mobility for subsequent mass analysis by the mass spectrometer.

Abstract: Systems and methods for concentrating solar energy without tracking the sun are provided. In one embodiment, the invention relates to a solar collector assembly for collecting and concentrating light for solar cell assemblies, the collector assembly including an array of solar collectors, each including a funnel shaped collector including a side wall defining a tapered opening having a base aperture and an upper aperture, the side wall including an outer surface, and a solar cell assembly positioned at the base aperture, where the outer surface is coated with a material that substantially reflects light, where the upper aperture is wider than the base aperture, where the funnel shaped collector is configured to substantially confine light, incident via the upper aperture, within the funnel shaped collector until the light exits proximate the base aperture, and where the solar cell assembly is configured to capture light exiting the base aperture.

Abstract: Micro-cavity resonant sensors have outer surfaces that are functionalized using click chemistry, e.g., involving a cycloaddition reaction of an alkyne functional group and an azide functional group. A first polymer linking element binds to an outer surface of the micro-cavity and has an azide functional group, which bonds to an alkyne functional group of a second polymer linking element as a result of a cycloaddition reaction. A functionalization element such as an antibody, antigen or protein for sensing a target molecule is bound to the second linking element.

Abstract: Micro-cavity gas or vapor sensors and gas or vapor detection methods. Optical energy is introduced into a resonant micro-cavity having a deformable coating such as a polymer. The coating swells or expands when it is exposed to or absorbs a gas or vapor, thereby changing the resonant wavelength of optical energy circulating within the micro-cavity/coating. Expansion or swelling of the coating may be reversible such that it contracts when gas or vapor diffuses from the coating. The coating deformation and/or a change of one or more optical properties of the optical energy circulating within the micro-cavity are used to detect the presence of the gas or vapor or molecules or particulates thereof.