Microwires

What is a microwire?

Microwire is a wire of small diameter for manufacturing of windings of electric micromachines, coils of measuring and regulating devices. Microwires are obtained from various metals and alloys: conductive, resistive, magnetic, semiconductor with their simultaneous coating with glass insulation, with a diameter of less than 1 μm to tens of microns, including precious metals (Au, Pt, Ag, etc.). 

Applying microwires

  • special applications wires (biological use, underwater, space, toxic environments);
  • measuring converters of non-electrical quantities (temperature, pressure, speed, force, mass, etc.);
  • inductive converters;
  • transformers, windings of electric motors;
  • high-resistance resistive devices, high-voltage dividers;
  • complexes of filamentary nanostructures;
  • electrodes.

Casted microwires in glass insulation

The casting process and equipment make it possible to obtain microwires with a diameter from less than 1 pm to tens of pm, incl. from non-plastic materials, for example, cast iron. Casted microwires are produced from liquid metal (alloys) or from precious materials - Au, Cu, Ag, Pt, with their simultaneous coating with glass insulation. Ultra-thin diameter (up to less than 1 μm) provides a significant reduction in the mass and dimensions of the elements from the microwire, reduces their mechanical, thermal and electrical inertia. Solid glass insulation provides high electrical strength and the ability to work in a wide range of temperatures (from -100 ° C to more than 400 ° C), under chemically complex and radiation conditions, resistant to high pressures.

Possible applications:

  • measuring converters of non-electrical quantities (temperature, pressure, speed, force, mass, etc.);
  • inductive converters;
  • transformers, windings of electric motors;
  • high-resistance resistive devices, high-voltage dividers;
  • complexes of filamentary nanostructures.

 

Microconductors amorphous with magnetic bistability

A distinctive feature of cast microwires with an amorphous structure of special alloys is their magnetic bistability. The magnetization reversal of such microwires is carried out in one jump (the Barhauzen effect). The critical length of the microwire segments on which the bistability effect is preserved is 5 mm and is 10-20 times smaller than for bistable bands and wires obtained by other methods, and the rate of magnetization reversal of bistable microwires is several times greater than that of analogues.

Core material Fe-based alloys
Insulation Glass and others.
d is the diameter of the core from less than 1 μm to tens of μm
D - outer diameter D / d (0.7 ÷ 1.7) + 10 / d
Resistance 5 - 500 kΩ / Ohm
Start field 1 - 200 A / m
Magnetization reversal time 10 - 15 us
Coefficient of squareness ≤ 5 %
Critical length ≥ 5 мм

Bistable microwires are intended for use in code markers for encoding goods (RFID), documents, securities, coding and remote control of actuators, sensor sensors, converters of electrical and non-electrical quantities; pulse transformers, chokes, delay lines.

 

Microwire magnetic with natural ferromagnetic resonance

A characteristic difference of microwires is the presence of a natural ferromagnetic resonance in the frequency range 1-15 Ghz. The existence of natural ferromagnetic resonance in microwire allows the creation on its basis of broadband radio-absorbing materials with attenuation of tens of decibels.

Magnetic microwires are designed for use in radio absorbing materials: components (sheets, bars, bundles, films), coatings (fabrics, paints) capable of absorbing electromagnetic radiation over a wide frequency range with low reflection coefficient.

Possible applications - protection of premises, chambers, communication cables, radio-absorbing materials; non-metallic composites; non-woven and woven materials; paints; military equipment shielding.

 

Microwire semiconductor and semimetallic

Microwires with semiconductor and semimetal wires have a number of features compared to massive semiconductor crystals. This is due to the high speed of casting of these microwires and allows 2-3 times to expand the mutual solubility of the components of solid solutions, and also to obtain crystals that are not synthesized at all by conventional methods, which makes it possible to create fundamentally new microconverters on their basis.

They have unique properties: linear magneto-resistance in weak fields, high coefficient of thermopower. etc. Due to the micron diameter of the core (up to 0.2 [Jm), commensurate with different characteristic lengths of semiconductor and semimetallic materials, such microwires are unique objects for the study of classical and quantum dimensional effects.

Possible applications are galvanomagnetic elements and converters; converters of electrical and non-electrical quantities; thermoelectric converters (thermocouples, micro-refrigerators); infrared and hard radiation detectors; Germanium optical fibers for the transmission of information in the infrared range.

Core material Bi, Sb
Bi1-x-Sbx
InSb1-x-A
(A:InBi, Ge, NiSb, Bi)
Bi2Te3
Sb2Te3
d, μm is the diameter of the core 0,2 - 100 10 - 100 20 - 70
10 - 100
D / d
L, m 1 - 10 1 - 100
Specific resistance, ρ, Ωm (1 - 2) 10-7 (1 - 500) 10-5 (2 - 10) 10-6
Thermoelectromotive force, V / s 80 - 100 - -150 ÷ +180
Magnetic sensitivity, R / R (B = 3T) 1 - 3 3 - 7 -

 


Casted microwire with improved characteristics for the stress effect

Development of improved cast microwires in glass insulation with amorphous and nanocrystalline living material with increased tensile strength and high magnetic properties (stress effect).

Use - for the manufacture of certain types of concrete and providing remote control of deformations of concrete structures.

 

Microwire conductor and resistive

Core material: Cu, Ni, Au, Ag, Pb and others Cu, Ni, Au, Ag, Pb and others
Alloys based on Fe, Ni, Co Alloys based on Fe, Ni, Co
d - core diameter less than 1 μm to tens of μm
D - external diameter D/d (0,7 ÷1,7) + 10/d
Resistance 0,05 - 1000 k Ω/м
Temperature coefficient of resistance: conductor microwires (4 ÷ 6) 10-3 К-1
Resistive Microwire (5 ÷ 50) 10-6 К-1
Breakdown voltage: direct current 2,5 ÷ 6 kW
alternating current 1,5 ÷ 3 kW
Rupture strength (5 - 10) 10-2 N (5 - 10) 10-2 Н
Weight 0,25 ÷ 6 g / km 0,25 ÷ 6 g/km

 

Tensomagnetic elements based on composite integral threadlike structures with magnetic microfilaments

Based on the technology for the production of composite filamentary integral structures from magnetic microwires that exhibit a magnetoelastic effect, tensor-magnetic sensors have been developed that exhibit the Villari effect. The number of threads in one composite filamentary integral structures is from 100 to 200 (depending on the destination). The diameter of the microwire used is from 8 to 20 μm. The total diameter of the composite filamentary integral structures is from 120 to 200 μm at a length of 140-150 mm. The coercive force is from 30 to 150. Their appearance and basic parameters consist of:

  • Length 5 ... 50 mm
  • Diameter of the core 120 ... 200 μm
  • Winding thickness 40 μm
  • Number of winding turns 100 ... 200
  • Strain gage sensitivity 80 ... 150
  • Operating frequencies 1, 10 and 20 kHz

Filamentary nanostructured compositions
The company conducts work on the creation of filamentary nanostructural compositions  from a number of metals, semimetals, semiconductors. Nanostructures is a close-packed bundle of electrically conductive nanowires in individual glass insulation, each bundle is covered with a common glass sheath. They can contain hundreds of thousands and millions of separate insulated nanowires with core diameters from 50 to 200 nm with a total diameter of 20-200 μm. The length of the obtained filamentary nanostructural compositions is up to 20-30 cm.
On their basis, it is possible to manufacture microthermocouples and point-based mi-culerators, which can be used in medicine and biology to diagnose and treat various diseases associated with blood vessels and vascular ducts of other organs.

Micropipettes
”ELIRI” provides services for the production of glass micropipettes and microelectrodes used in intracellular recording, micro perfusion and micro injections.
There is a technological equipment. Our experience in the field of micropipette technology guarantees accuracy and high quality.

The Wigonde sensors
The Wigonde sensors are one of the directions of the measurement and control system. Such a sensor responds to magnetic fields and generates signals in the range of several volts, provided that the intensity of the control magnetic field exceeds the magnitude of the field strength of the ignition. In this case, the Wiegand sensor does not require any power source, its output signal is practically independent of the frequency of the field change, and can be used in the widest range of operating temperatures.
The Wigand sensor is capable of storing data, it is very successfully used in the considered identification cards.

Biomedical micro-nano probes based on gold
Field of application- electronics and materials for biomedicine

Micro-wire point electrodes made of precious metals (Au, Pt)
The area of ​​possible use is for medical and biological applications.

years
of
work
M km
TOTAL LENGTH
MANUFACTURED
WIRES
µm
DIAMETER
OF MICROWIRES
LESS THAN 1 micro m

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