Enhanced Microfluidic Electromagnetic Measurements

A method comprising:

• causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid, wherein an optical index of refraction of a fluid constituting either sheath flow is much less than an optical index of refraction of the core fluid;
• and
• measuring an optical property in the channel between an optical source and an optical detector.

An apparatus comprising:

• means for causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid, wherein a dielectric constant of a fluid constituting either sheath flow is substantively less than a dielectric constant of the core fluid, and wherein flow in the channel is laminar;
• and
• means for determining impedance in the channel based on measurements at a first pair of one or more pairs of electrodes.

A non-transient computer-readable medium carrying one or more sequences of instructions, wherein execution of the one or more sequences of instructions by one or more processors causes an apparatus to:

• receive first data indicating measurements of impedance in a channel between a first pair of electrodes, wherein a core fluid flows into the channel between two sheath flows of one or more sheath fluids different from the core fluid, wherein a dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid, and wherein flow in the channel is laminar;
• and
• determine impedance of a particle in the core fluid based at least in part on the first data.

An apparatus comprising:

• means for receiving first data indicating measurements of impedance in a channel between a first pair of electrodes, wherein a core fluid flows into the channel between two sheath flows of one or more sheath fluids different from the core fluid, wherein a dielectric constant of a fluid constituting either sheath flow is much less than a dielectric constant of the core fluid, and wherein flow in the channel is laminar;
• and
• means for determining impedance of a particle in the core fluid based at least in part on the first data.

A method comprising:

• causing a core fluid to flow into a channel between two sheath flows of one or more sheath fluids different from the core fluid, wherein a value of a first electromagnetic property of a fluid constituting either sheath flow is substantially different from a value of the first electromagnetic property of the core fluid, and wherein flow in the channel is laminar;
• and
• measuring a second electromagnetic property in the channel using an electromagnetic signal that is concentrated in the core fluid by a difference in the value of the first electromagnetic property of either sheath flow and the value of the first electromagnetic property of the core fluid.