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Multi-role wireless passive sensor is ‘the world’s smallest’

13 December, 2021

A Slovak company claims to have come up with the world’s smallest passive wirelesss sensor technology, which can directly measure variables such as pressure, temperature and magnetic field strength, as well as derived quantities such as torsion, stress and flow, without making contact or needing a direct power supply.

RVmagnetics’ MicroWire sensor consists of a thin (3-70µm diameter), elastic “wire” with a metallic alloy core and a glass outer coating, which can be embedded in almost any material – including plastics, concrete, steel, composites and ceramics – without affecting their properties. The sensing wires are typically 1-4cm long.

An excitation coil located up to 10cm away from the wire generates an AC magnetic field to produce a response from the wire which is sensed using another coil. Unless it is an electrically or magnetically noisy area, the excitation coil needs only a few mA to power it. The MicroWire is sensitive to temperature, pressure and its position in a magnetic field, and this information is picked up by the sensing coil. Up to 10,000 real-time measurements can be made every second. The signals are filtered and amplified and then digitalised in an ARM processor chip, ready for post-processing by the user’s software.

The sensors can withstand harsh acidic and alkaline environments, and they are not affected by noisy electromagnetic environments or high temperatures. The technology does not produce sparks, so can be used in potentially hazardous environments. If a sensor breaks, two separate measurements are obtained.

RVmagnetics says that its sensors are best suited for applications where no other sensor could do the job. Potential applications include:
● preventive and predictive maintenance;
● real-time non-destructive testing;
● increasing the safety, efficiency and effectiveness of applications or production processes; and
● predicting material defects.

RVmagnetics’ wireless sensing technology is based on thin MicroWires consisting of a metallic allow core coated with glass

The MicroWire system is not an off-the-shelf technology. Rather, RVmagnetics custom-designs sensing systems to meet specific users’ needs, calibrated to achieve their required ranges and accuracy. It specifies the most appropriate MicroWire composition, diameter, length and position, based on the application. The company has already worked with customers in areas including manufacturing, civil engineering, transportation and IoT.

RVmagnetics was founded in 2015 by a magnetics expert, Professor Rastislav Varga, who is now backed by a team of more than a dozen r&d professionals with a combined experience of more than 30 years in areas such as chemistry, physics, engineering and electronics. The company has developed the technology for drawing and quenching molten alloys and glass rapidly to produce the MicroWires.

RVmagnetics:  Twitter  LinkedIn  Facebook

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