According to Cisco’s Annual Internet Report, by 2023 there will be nearly 30 billion network-connected devices (in 2018 there were around 18.4 billion). IoT devices make 50% (14.7B) of the whole by 2023, compared to 33% (6.1B) in 2018. In the IoT industry, magnetic sensors alone, occupy a proportion of around 10% in smart sensors applications. Moreover, it has been forecasted that the magnetic sensor markets will grow by 7%/year since 2016, reaching around U.S. $2.5 billion in 2022. This growth can purely bring positive economical and day-to-day prospects – only if we ensure that the components of the IoT concept are precise, safe, and fairly priced.

During such challenging times most industries, countries, and global economies are facing in 2021, companies are looking for faster and less expensive shortcuts. Some of them want to build their competitive advantages, some just need to purely survive. In the IoT world sensors are that essential entity which is supposed to provide the valid insurance of receiving correct information. Sensors that provide physical data from various environments, the quickest way possible are now the most obvious choice to make. 

Different communities, industries, and cultural surroundings around the globe can already see the security, efficiency, and general quality of their activities improve drastically thanks to sensor technologies and thus IoT. This concept is wholly blending into our daily lives (think of the booming market for smartwatches, smart home solutions, connected cars, increasingly smart mobile phones, and so on), making it inevitable for both sensors and sensor technologies to become as small, versatile, and competent as they can get!

Magnetism and sensors of the present

The magnetism & sensors connection are hidden jewels within Industry 4.0 and the Internet of Things as such.  

Sensors of magnetic nature traditionally detect the magnetic fields in the form of directions, flux, strength. Measurements gathered through magnetic fields with the above-mentioned methods can create standard off-shelf measurement devices and be implemented in medium-accuracy applications (i.e smartphone compass).

They achieve this by providing calibrations of directions, positions, angles, rotation of various objects they are integrated on. Eventually, magnetic sensors became useful measurement tools in military applications, medical devices, the automotive industry, robotics, general industrial measurements, etc. 

Tiny ones for the future normal

Currently, there are different types of magnetic sensors productized and available in the mass market like Hall sensors, superconducting quantum interference device (SQUID), fluxgate sensors, induction magnetometer, semiconducting magneto-resistors, Eddy current sensors, magnetic encoders, permanent magnet linear contactless displacement sensors, reed contact, and many more.

However, as the IoT is being vastly adopted into both daily and industry common habits – now every application brings the need for more miniature and less space-occupying and surely inexpensive designs (i. e. mobile phones, medical devices, industrial integrated sensors). Even post-Cold War NASA adopted the slogan “Faster, Better, Cheaper” (FBC) when designing the new satellites.

As much as the size and inexpensive design are essential qualities for magnetic sensors, there are other drawbacks of the currently available technologies that increase expectations for sensors of the future. 

We are talking about forces like external magnetic fields interfering and swaying the measurement of current flow for Hall sensors, or in that matter, the temperature effects on the electrical resistance and eventually, the sensitivity of these sensors; or temperature/force resistance levels and overall the price for MEMS sensors; and many more similar cases where one disadvantage of a sensor cannot be fixed with another sensor. Or can it?

100 years and 25 years of intense scientific effort in applied magnetism brought to life the understanding that, by using modern physical phenomena and processes, it is now possible to develop miniature embeddable sensors and read measured quantities from a greater distance. 

This sort of magnetism-sensors-IoT fellowship has already been identified in the industry. A sensing system that incorporates magnetic principles without compromising the size, durability, cost, and overcoming the negative effects of external magnetic/electric fields, hazardous, alkaline, extreme temperature environments, adding to qualities like contactless, real-time measurements; the RVmagnetics MicroWire sensor .

MicroWire: How does it work, and what values does it add?

The sensors: these glass-coated sensors commonly use soft magnetic materials — meaning they are easily magnetized and demagnetized — but also metals that exhibit magnetostriction, meaning they change their shape when subjected to a magnetic field. The sensing can happen through the magnetic field from inside almost any material.

The MicroWire sensor measurements have no hysteresis (unlike for example Hall sensors), it is linear (see on the diagram) from the principle of the measurement.

Linearity is valid up to the highest value of the range. The range can be adjusted to almost any value since the feature of MicroWire’s response (no hysteresis/linearity) works from very low to very high fields. 

Additionally, there is no temperature dependence on the magnetic response of MicroWire. 

The sensing: sensing is contactless. It is important to mention that the MicroWire is a passive element with neither wiring attached to it nor data being gathered in it. The data itself is gathered through the sensing head and the electronics. The sensing head consists of two copper coils (excitation coil gives out the magnetic field, sensing coil “gathers” the MicroWires response in the local physical environment).

RVmagnetics technology employs switching between two stable magnetic states to sense different parameters. The technical solution allows for separation of the contribution of different parameters and the switching field depends on temperature, magnetic field, vibrations, stress, torque, el. current and other physical quantities. 

This data is gathered on a Central Processing Unit (CPU) which also acts as an AD converter.

It is exciting to see the possibilities that this kind of technology is bringing into the IoT world. To be added to that Artificial Intelligence, Industrial applications, Medical technologies, and the future in question – of course.

A sensor thinner than a human hair is now able to conduct “data mining” of physical quantities like temperature, pressure, magnetic field, electric current, humidity… all at the same time. A unique technical solution transforms the switching field into switching time which makes for easier and better measurements: 1 gram of metallic alloy is enough to manufacture 10.000 of these little sensors making it one of the more inexpensive members of the IoT élite.

In conclusion: this tiny sensor manages real-time non-destructive testing and becomes that one sensor filling other sensors’ disadvantages through qualities like:

• The MicroWire sensor measurements have no hysteresis, it is linear from the principle of the measurement.
• External magnetic fields do not bias the measurements from MicroWire
• No temperature effects on the electrical resistance or sensitivity of the MicroWire
• Law production and routine costs (1 kilogram of alloy can produce 40,000 kilometers (~ Earth’s circumference at the Equator) of MicroWire at several hundred meters/minute.)
• Introduction into almost any material without causing structural flaws/material defects
• Sensitivity and frequency (i.e., frequency of 10.000 times/second)

Have the MicroWire embedded into an electric motor, a composite structure, a rechargeable battery, or into the walls of your house and you got yourself a tiny fellow from industry 4.0 making things smarter, safer, and more effective for you.