US 8,506,837 B2 · Field-responsive fluids

Abstract

A field-responsive fluid which enters a semi-solid state in the presence of an energy field is improved by use of a plurality of energy field responsive particles which form chains in response to the energy field. The particles can be (a) composite particles in which at least one field-responsive member having a first density is attached to at least one member having a second density that is lower than the first density, (b) shaped particles in which at least one field-responsive member has one or more inclusions, and (c) combinations thereof. The particles improve the field-responsive fluid by reducing density without eliminating field-responsive properties which afford utility. Further, a multi-phase base fluid including a mixture of two or more substances, at least two of which are immiscible, may be used. The multi-phase base fluid improves the field-responsive fluid because surface tension between the boundaries of the immiscible substances in conjunction with chains formed by field-responsive particles tends to stop or retard creep flow, resulting an improved dynamic or static seal.

Claims29

Dependent claims

Apparatus for causing a fluid to enter a semi-solid state in the presence of a magnetic field, comprising:

a plurality of energy field responsive particles which form chains in response to the magnetic field, the particles selected from the group consisting of:
particles in which at least one field-responsive member having a first density is attached to at least one member having a second density that is lower than the first density;
shaped particles in which at least one field-responsive member has one or more inclusions;
and combinations thereof;
a multi-phase base fluid, the multi-phase base fluid mitigating fluid creep between the plurality of energy field responsive particles;
and
wherein the plurality of energy field responsive particles comprises, a 55% particle volume fraction of particles having particle sizes between 100-300 μm, a 35% particle volume fraction of particles having particle sizes between 20-30 μm , a 10% particle volume fraction of particles having particle sizes between 2-5 μm and wherein the plurality of energy field responsive particles are 60% of a volume fraction of the fluid, the particle sizes reducing a size of a gap between the plurality of energy field responsive particles and mitigating fluid creep.

4 more elements

Dependencies are inferred from the claim text.

Field-responsive fluids

Life of this patent

Field-responsive fluids

Life of this patent

Abstract

Claims29