Abstract: An electrostatic lens for transporting charged particles in an axial direction includes a first group of first electrodes configured to receive a first DC potential from a DC voltage source, and a second group of second electrodes configured to receive a second DC potential from the DC voltage source different from the first DC potential. The first electrodes are interdigitated with the second electrodes. The first group and/or the second group has a geometric feature that progressively varies along the axial direction. The lens generates an axial potential profile that progressively changes along the axial direction, and thereby reduces geometrical aberrations. The lens may be part of a charged particle processing apparatus such as, for example, a mass spectrometer or an electron microscope.

Abstract: A microfluidic apparatus for forming one or more droplets of an aqueous fluid suspended in a non-aqueous fluid is described. The microfluidic apparatus includes a first microfluidic channel configured for flowing an aqueous fluid through the first microfluidic channel and a second microfluidic channel fluidically connected to the first microfluidic channel and adapted to flow a non-aqueous fluid through the second microfluidic channel into the first microfluidic channel. A microfluidic reservoir fluidically connected to the first microfluidic channel and configured to receive a plurality of droplets of the first aqueous fluid. The microfluidic apparatus further includes a first electrode and a second electrode positioned such that application of voltage to the first electrode moves one or more droplets of the aqueous fluid in a first direction and application of voltage to the second electrode moves one or more droplets of the aqueous fluid in a second direction.

Abstract: An electrostatic lens for transporting charged particles in an axial direction includes a first group of first electrodes configured to receive a first DC potential from a DC voltage source, and a second group of second electrodes configured to receive a second DC potential from the DC voltage source different from the first DC potential. The first electrodes are interdigitated with the second electrodes. The first group and/or the second group has a geometric feature that progressively varies along the axial direction. The lens generates an axial potential profile that progressively changes along the axial direction, and thereby reduces geometrical aberrations. The lens may be part of a charged particle processing apparatus such as, for example, a mass spectrometer or an electron microscope.

Abstract: An ion guide includes electrodes elongated along an axis from an entrance end to an exit end and spaced around the axis to surround an interior. The electrodes have polygonal shapes with inside surfaces disposed at a radius from the axis and having an electrode width tangential to a circle inscribed by the electrodes. An aspect ratio of the electrode width to the radius varies along the axis. The electrodes are configured to generate a two-dimensional RF electrical field in the interior having a multipole composition comprising one or more lower-order multipole components and one or more higher-order multipole components and varying along the axis in accordance with the varying aspect ratio, and having an RF voltage amplitude that varies along the axis.

Abstract: An ion guide includes electrodes elongated along an axis from an entrance end to an exit end and spaced around the axis to surround an interior. The electrodes have polygonal shapes with inside surfaces disposed at a radius from the axis and having an electrode width tangential to a circle inscribed by the electrodes. An aspect ratio of the electrode width to the radius varies along the axis. The electrodes are configured to generate a two-dimensional RF electrical field in the interior having a multipole composition comprising one or more lower-order multipole components and one or more higher-order multipole components and varying along the axis in accordance with the varying aspect ratio, and having an RF voltage amplitude that varies along the axis.

Abstract: An electrostatic lens for transporting charged particles in an axial direction includes a first group of first electrodes configured to receive a first DC potential from a DC voltage source, and a second group of second electrodes configured to receive a second DC potential from the DC voltage source different from the first DC potential. The first electrodes are interdigitated with the second electrodes. The first group and/or the second group has a geometric feature that progressively varies along the axial direction. The lens generates an axial potential profile that progressively changes along the axial direction, and thereby reduces geometrical aberrations. The lens may be part of a charged particle processing apparatus such as, for example, a mass spectrometer or an electron microscope.

Abstract: A microfluidic apparatus for separating a droplet of an emulsion in a microfluidic environment is described. The microfluidic apparatus includes a flow cell comprising a first microfluidic channel configured for flowing a first fluid through the flow cell and a second microfluidic channel configured for flowing a stream of a second fluid through the flow cell. The microfluidic apparatus further comprises a first electrode positioned at the first microfluidic channel and a second electrode positioned at the second microfluidic channel on an opposite side of the interface with respect to the first electrode. The first electrode, the second electrode, and the first and second microfluidic channels are configured to generate a non-uniform electric field gradient in the microfluidic apparatus.

Abstract: An ion guide includes electrodes elongated along an axis from an entrance end to an exit end and spaced around the axis to surround an interior. The electrodes have polygonal shapes with inside surfaces disposed at a radius from the axis and having an electrode width tangential to a circle inscribed by the electrodes. An aspect ratio of the electrode width to the radius varies along the axis. The electrodes are configured to generate a two-dimensional RF electrical field in the interior having a multipole composition comprising one or more lower-order multipole components and one or more higher-order multipole components and varying along the axis in accordance with the varying aspect ratio, and having an RF voltage amplitude that varies along the axis.

Abstract: The invention relates generally to methods and apparatus that gravitationally transfer cells from a first medium to a second medium. More specifically, the invention relates to a novel microfluidic device. The microfluidic device includes a cell transfer region, a cell settling channel, a waste channel, a cell output channel, and an input medium channel. The cell settling channel, the waste channel, and the cell output channel extend from, are in fluid communication with, and are smaller in cross section than the cell transfer region. The cell output channel is substantially perpendicular to the cell settling channel and to the waste channel. The input medium channel extends from and is in fluid communication with the cell output channel.

Abstract: A microfluidic apparatus for separating a droplet of an emulsion in a microfluidic environment is described. The microfluidic apparatus includes a flow cell comprising a first microfluidic channel configured for flowing a first fluid through the flow cell and a second microfluidic channel configured for flowing a stream of a second fluid through the flow cell. The microfluidic apparatus further comprises a first electrode positioned at the first microfluidic channel and a second electrode positioned at the second microfluidic channel on an opposite side of the interface with respect to the first electrode. The first electrode, the second electrode, and the first and second microfluidic channels are configured to generate a non-uniform electric field gradient in the microfluidic apparatus.

Abstract: The invention relates generally to methods and apparatus that gravitationally transfer cells from a first medium to a second medium. More specifically, the invention relates to a novel microfluidic device. The microfluidic device includes a cell transfer region, a cell settling channel, a waste channel, a cell output channel, and an input medium channel. The cell settling channel, the waste channel, and the cell output channel extend from, are in fluid communication with, and are smaller in cross section than the cell transfer region. The cell output channel is substantially perpendicular to the cell settling channel and to the waste channel. The input medium channel extends from and is in fluid communication with the cell output channel.

Abstract: A droplet-based microfluidic device having a first confining plate, a second confining plate, and an actuator. Each confining plate includes a respective substrate and hydrophobic layer having a planar major surface. The first confining plate additionally includes a common electrode between its hydrophobic layer and substrate. The second confining plate includes an electrode array between its hydrophobic layer and substrate. The confining plates are disposed opposite one another with their major surfaces separated from one another by a gap. The actuator is to impart oscillatory sliding motion between the confining plates in a direction principally parallel to the major surfaces. The oscillatory sliding motion effectively allows voltages applied between the common electrode and the electrodes of the electrode array to move a microfluidic droplet located in the gap across the major surfaces without sticking.

Abstract: In a tandem mass spectrometry system, a first mass analyzer filters parent ions using a wide mass passband with a narrow rejection notch defined according to a modulation format. A wide mass range of parent ions is transmitted to an ion fragmentation device. Daughter ions produced thereby are transmitted to a second mass analyzer to produce a daughter ion mass spectrum. The modulation of the measured daughter ion mass spectrum, when correlated with the passband modulation of the first mass analyzer (i.e., parent ion spectrum), allows definitive identification of each daughter mass peak with the appropriate parent ion. Due to the wide mass passband, the ion detector signal is in proportion to the increased ion flux passed by the first mass analyzer.

Abstract: An apparatus for controlling the motion of a particle and a method for using the same are disclosed. The apparatus includes a channel containing liquid between first and second electrodes. The apparatus also includes an array of variable impedance elements, each variable impedance element connecting the first electrode to a corresponding location in the channel by a path having an average impedance that is continuously variable between first and second impedances when averaged over an update time interval. A controller sets the average impedance of each of the variable impedance elements such that a particle in the channel moves in a predetermined direction when voltage is applied between the first and second electrodes. At least one of the variable impedance elements has an average impedance that is intermediate between the first and second impedances.

Abstract: In a tandem mass spectrometry system, a first mass analyzer filters parent ions using a wide mass passband with a narrow rejection notch defined according to a modulation format. A wide mass range of parent ions is transmitted to an ion fragmentation device. Daughter ions produced thereby are transmitted to a second mass analyzer to produce a daughter ion mass spectrum. The modulation of the measured daughter ion mass spectrum, when correlated with the passband modulation of the first mass analyzer (i.e., parent ion spectrum), allows definitive identification of each daughter mass peak with the appropriate parent ion. Due to the wide mass passband, the ion detector signal is in proportion to the increased ion flux passed by the first mass analyzer.

Abstract: The invention provides an apparatus and method for sequencing and identifying a biopolymer. The invention provides a first electrode, a second electrode, a first gate electrode, a second gate electrode, a gate voltage source and a potential means. The gate electrodes may be ramped by a voltage source to search and determine a resonance level between the first electrode, biopolymer and second electrode. The potential means that is in electrical connection with the first electrode and the second electrode is maintained at a fixed voltage. A method of biopolymer sequencing and identification is also disclosed.

Abstract: A mass analyzer comprises a pair of planar electrode structures. The electrode structures are disposed opposite to each other, parallel to each other, and axially offset from each other. The electrode structures are configured to generate, in response to an applied voltage, a cylindrically-symmetric, annular electric field comprising an annular radially focusing central lens region surrounding an axis of symmetry, and an annular mirror region surrounding the annular radially focusing central lens region.

Abstract: A mass analyzer comprises a pair of planar electrode structures. The electrode structures are disposed opposite one another, parallel to one another, and axially offset from one another. One of the pair of planar electrodes comprises an opening. The mass analyzer comprises an ion mirror disposed between the pair of planar electrodes. A mass spectrometer and a mass spectrometry method are also described.

Abstract: A mass analyzer comprises a pair of planar electrode structures. The electrode structures are disposed opposite one another, parallel to one another, and axially offset from one another. One of the pair of planar electrodes comprises an opening. The mass analyzer comprises an ion mirror disposed between the pair of planar electrodes. A mass spectrometer and a mass spectrometry method are also described.

Abstract: A mass analyzer comprises a pair of planar electrode structures. The electrode structures are disposed opposite to each other, parallel to each other, and axially offset from each other. The electrode structures are configured to generate, in response to an applied voltage, a cylindrically-symmetric, annular electric field comprising an annular radially focusing central lens region surrounding an axis of symmetry, and an annular mirror region surrounding the annular radially focusing central lens region.