Category Archives: IoT

Sensors at the Heart of IoT

IoT, or the Internet of Things, depends on sensors. So much so, there would not be any IoT, IIoT, or for that matter, any type of Industry 4.0, at all, without sensors. As the same factors apply to all the three, we will use IoT as a simplification. However, some basic definitions first.

As a simple, general definition, IoT involves devices intercommunicating with useful information. As their names suggest, for IIoT and Industry 4.0, these devices are mainly located in factories. While IIoT is a network of interconnected devices and machines on a plant floor, Industry 4.0 goes a step further. Apart from incorporating IIoT, Industry 4.0 expands on the network, including higher level systems as well. This allows Industry 4.0 to process and analyze data from IIoT, while using it for a wider array of functions, including looping it back into the network for control.

However, the entire network has sensors as its basis, supplying it with the necessary raw data. Typically, the output from sensors is in the form of electrical analog signals, and IoT creates the fundamental distinction between data and information.

This distinction is easier to explain with an example. For instance, a temperature sensor, say, a thermistor, shows electrical resistance that varies with temperature. However, that resistance is in the form of raw data, in ohms. It has no meaning to us, until we are able to correlate it to degrees.

Typically, we measure the resistance with a bridge circuit, effectively converting the resistance to voltage. Next, we apply the derived voltage to a measuring equipment that we have calibrated to show voltage as degrees. This way, we have effectively converted data into information useful to us, humans. However, we can still use the derived voltage to control an electric heater or inform a predictive maintenance system of the temperature of a motor.

But information, once we have derived it from raw data, has almost endless uses. This is the realm of IoT, intercommunicating useful information among devices.

To be useful for IoT, we must convert the analog data from a sensor to a digital form. Typically, the electronics required for doing this is the ADC or Analog to Digital Converter. With IoT applications growing rapidly, users are also speeding up their networks, thereby handling even larger amounts of data, making them more power efficient.

Scientists have evolved a new method for handling large amounts of data that does not require the IoT devices to have large amounts of memory. The devices send their data over the internet to external data centers, the cloud. There, other computers handle the proper storing and analysis of the data. However, this requires higher bandwidth and involves latency.

This is where the smart sensor makes its entry. Smart sensors share the workload. A sensor is deemed smart when it is embedded within a package that has electronics for preprocessing, such as for signal conditioning, analog to digital conversion, and wireless transmission of the data. Lately, smart sensors are also incorporating AI or Artificial Intelligence capabilities.

Ultrasonic Sensors in IoT

For sensing, it has been a standard practice to employ ultrasonic sensors. This is mainly due to their exceptional capabilities, low cost, and flexibility. With IoT or the Internet of Things now virtually entering most industries and markets, one can now find ultrasonic sensors in newer applications in healthcare, industrial, and smart offices and homes.

As their name suggests, ultrasonic sensors function using sound waves, especially those beyond the hearing capability of humans. These sensors typically send out chirps or small bursts of sound in the range of 23 kHz to 40 kHz. As these chirps bounce back from nearby objects, the sensor detects them. It keeps track of the time taken by the chirp for a round trip and thereby calculates the distance to the object based on the speed of sound.

There are several benefits from using ultrasonic sensors, the major one being very accurate detection of the object. The effect of material is also minimal—the sensor uses sound waves and not electromagnetic waves—the transparency or color of the object has minimum effect on the readings. Additionally, this also means that apart from detecting solid objects, ultrasonic sensors are equally good at detecting gases and liquid levels.

As ultrasonic sensors do not depend on or produce light during their operation, they are well-suited for applications that use variable light conditions. With their relatively small footprints, low cost, and high refresh rates, ultrasonic sensors are well-established over other technologies, like inductive, laser, and photoelectric sensors.

According to a recent study, the smart-office market will likely reach US$90 billion by 2030. This is mainly due to a surging demand for sensor-based networks, brought about by the need for safety and advancements in technology. Ultrasonic sensors will be playing an expanded role due to industry and local regulations supporting increased energy efficiency for automating different processes around the office.

A prime example of this is lighting and HVAC control in offices. Ultrasonic sensors are adept at detecting populated rooms in offices all through the day. This data is useful in programming HVAC systems, for keeping rooms hot or cool when populated, and turning the system off at the end of the day, kicking back on at first arrival.

Similarly, as people enter or leave rooms or areas of the office, ultrasonic sensors can control the lights automatically. Although the process looks simple, the energy savings from cutting back on lighting and HVAC can be huge. This is especially so for large office buildings that can have many unoccupied office spaces. For sensing objects across large areas, ultrasonic sensors offer ideal solutions, with detecting ranges of 15+ meters and detecting beam angles of >80°.

Additionally, smart offices can also have other smart applications like hygiene and touchless building entry devices. Touchless devices include automatic door entries and touchless hygiene products include faucets, soap dispensers, paper towel dispensers, and automatically lifting waste bin lids. During the COVID-19 pandemic, people’s awareness of these common applications has increased as public health and safety became critical for local offices and businesses.

Battery-Free Metal Sensor IoT Device

Many industrial, supply chain and logistics applications require advanced monitoring of temperature, strain, and other parameters during goods transfer. One of the impediments of such requirements is a battery-powered device, typically involving its cost and maintenance overheads. A global leader in digital security and identification in the IoT or Internet of Things, Identiv, Inc., has developed a sensory TOM or Tag on Metal label, collaborating with Asygn, a sensor and IC specialist from France. The advantage of this sensory label is it operates without batteries.

The new sensor label is based on the next-generation IC platform of Asygn, the AS321X. They can capture strain and temperature data near metallic objects. The AS321X series of UHF or ultra-high frequency RFID or radio-frequency identification chips is suitable for sensing applications and can operate without batteries. Identiv has partnered with Asygn to expand its portfolio of products. It now includes the new sensor-based UHF inlays compliant with RAIN RFID standards, enabling the identification of long-range products and monitoring their condition.

According to Identiv, their advanced RFID engineering solutions, combined with Asygn’s sensing IC platform, have created a unique product in the industry. Taking advantage of their production expertise, and the latest sensor capabilities of Asygn, these new on-metal labels from Identiv offer the first exclusive, on-metal, battery less sensing solution in the market.

Using their connected IoT ecosystems, Identiv can create digital identities for every physical object by embedding RFID-enabled IoT devices, labels, and inlays into them. Such everyday objects include medical devices, products from industries like pharmaceuticals, specialty retail, luxury brands, athletic apparel, smart packaging, toys, library media, wine and spirits, cold chain items, mobile devices, and perishables.

RFID and IoT are playing an increasing role in the complex and dynamic supply chain industry. The integration of RFID with IoT is developing automated sensing, and promoting seamless, interoperable, and highly secure systems by connecting many devices through the internet. The evolution of RFID-IoT has had a significant impact on revolutionizing the SCM or Supply Chain Management.

The adoption of these technologies is improving the operational processes and reducing SCM costs with their information transparency, product traceability, flexibility, scalability, and compatibility. RFID-IoT is now making it possible to interconnect each stage in the SCM to ensure the delivery of the right process and product at the right quantity and to the right place. Such information sharing is essential for improving coordination between organizations in the supply chain and improving their efficiency.

Combining RFID and IoT makes it easier to identify physical objects on a network. The system transmits raw data about an item’s location, status, movement, temperature, and process. IoT provides the item with an identification ID for tracking its physical status in real-time.

Such smart passive sensors typically power themselves through energy harvesting, specifically RF power. Each sensor is battery-free and has an antenna for wireless communication. As an RF reader interrogates a sensor, it uses the energy from the signal to transmit an accurate and fast reading. Many sensors form a hub that collects their data while communicating with other connected devices.

High-Efficiency Solar Cells for IoT Devices

As per expert estimates, by 2025, the worldwide number of IoT, or the Internet of Things, could rise to 75 billion. However, most IoT devices have sensors that run on batteries. Replacing these batteries can be a problem, especially for long-term monitoring.

Researchers at the Massachusetts Institute of Technology have now produced photovoltaic-powered sensors. These sensors can transmit data potentially for several years, before needing a replacement. The researchers achieved this by mounting thin-film perovskite cells as energy harvesters on low-cost RFID or radio-frequency identification tags. Perovskite cells are notoriously inexpensive, highly flexible, and relatively easy to fabricate.

According to the researchers, the future will have billions of sensors all around. Rather than power the sensors with batteries, the photovoltaic-powered sensors could use ambient light. It would be possible to deploy them and then forget them for months at a time or even years.

In a pair of papers the researchers have published, they have described the process of using sensors to monitor indoor and outdoor temperatures continuously over many days. No batteries were necessary for the sensors to transmit a continuous stream of data over a distance greater than five times that traditional RFID tags could. The significance of a long data transmission range means the user can employ one reader for collecting data simultaneously from multiple sensors.

Depending on the presence of moisture and heat in the environment, the sensors can remain under a cover or exposed for months or years before they degrade enough requiring a replacement. This can be valuable for applications requiring long-term sensing indoors as well as outdoors.

For creating self-powered sensors, many other researchers have tried solar cells for IoT devices. However, in most cases, these were the traditional solar cells and not the perovskite type. Although traditional solar cells can be long-lasting, efficient, and powerful under certain conditions, they are rather not suitable for universal IoT sensors.

The reason is, traditional solar cells are expensive and bulky. Moreover, they are inflexible and non-transparent—suitable and useful for monitoring the temperature on windows and car windshields. Most designs of traditional solar cells allow them to effectively harvest energy from bright sunlight, but not from low levels of indoor light.

On the other hand, it is possible to print perovskite cells using easy roll-to-roll manufacturing techniques costing only a few cents each. They can be made into thin, flexible, and transparent sheets. Furthermore, they can be tuned to harvest energy from outdoor or indoors lighting.

Combining a low-cost RFID tag with a low-cost solar power source makes them battery-free stickers. The combination allows for monitoring billions of products all over the world. Adding three to five cents more, it is possible to add tiny antennas working at ultra-high frequencies to the stickers.

Using a communication technique known as backscatter, RFID tags can transmit data. They reflect the modulated wireless signals from the tag and send it back to their reader. The reader is a wireless device, very similar to a Wi-Fi router, and it pings the tag. In turn, the tag powers up and using backscattering, sends a unique signal with information about the product on which it is stuck.

Energy from Vibrations for IoT Devices

Producing energy from vibrations is nothing new, and the world is always hungry for more clean energy. Engineers now have a new material that can convert simple mechanical vibrations all around it, to electricity. The electricity is enough to power most sensors on the Internet of Things ranging from spacecraft to pacemakers.

Engineers at the University of Toronto and the University of Waterloo have produced the material after decades of work. Their research has generated a novel compact electricity-generating system that they claim is reliable, low-cost, and green.

According to the researchers, their achievement will have a significant impact on social and economic levels, as it will reduce the reliance on non-renewable energy sources. They claim the world needs these energy-harvesting materials critically at this moment in time.

Energy harvesting technology produces small amounts of energy from external effects such as heat, light, and vibrations. For instance, an energy-harvesting device worn on the body could generate energy from body movements, such as from the legs or arm movements while walking. Most such devices produce enough energy to power personal health monitoring systems.

Based on the piezoelectric effect, the new material that the researchers have developed generates an electric current when there is pressure on it. Mechanical vibrations are one example of the type of pressure on the appropriate substance.

The piezoelectric effect is known and in use since 1880, and people have been using many piezoelectric materials like Rochelle salts and quartz. The technology has been in use for producing sonars, ultrasonic imaging, and microwave devices.

However, until now, most traditional piezoelectric materials in use in commercial devices have had a low finite capability for generating electricity. Moreover, most of these materials use Lead, which is detrimental to the environment and to human health as well.

The researchers solved both the above problems in one go. They grew a single large crystal of a molecular metal. This was a halide compound known as edabco copper chloride. For this, they used the Jahn-Teller effect, which is a well-understood concept in Chemistry, and offers a spontaneous geometric distortion in the crystal field.

The researchers proceeded to fabricate nanogenerators with the highly piezoelectric material they had produced. The nanogenerators had a significant power density and could harvest small mechanical vibrations in many dynamic circumstances involving those from automobile vehicles and even human motion. The nanogenerators neither used Lead nor needed non-renewable energy sources.

Each nanogenerator is just a shade smaller than an inch square, or 2.5 x 2.5 cm, and the thickness of a business card. It is possible to use them in various situations. They have a significant potential for powering sensors in vast arrays of electronic devices, such as those used by IoT or the Internet of Things, of which the world uses billions, and requires substantially more.

According to the researchers, the new material could have far-reaching consequences. For instance, the vibrations from an aircraft would be enough to power its systems for monitoring its various sensors. On the other side, vibrations from a person’s heartbeat could power their pacemaker, which can run without a battery.

Preserving IoT Battery Life

At MIT, researchers have built a wake-up receiver for IoT devices. The receiver uses terahertz waves to communicate, making the chip more than ten times smaller than contemporary devices. The receiver also includes authentication that helps protect it from certain types of attacks. The low power consumption of the chip means it can help preserve battery life in robots or tiny sensors.

The current trend is towards developing ever-smaller devices for IoT or the Internet of Things. For instance, sensors can be smaller than a fingertip, capable of making any object trackable. Most of these tiny sensors, however, have even tinier batteries that are nearly impossible to replace. Therefore, engineers need to incorporate a wake-up device in these sensors. It keeps the device in a low-power sleep mode when not operating, thereby preserving battery life. The new device from MIT is capable of protecting the device from certain attacks that could drain its battery rather quickly.

The present generation of wake-up receivers is typical of the centimeter scale. This is because their antennas need to be proportional to the length of the radio waves they use for communicating. On the other hand, the MIT team utilized the terahertz wave for the receiver. As these waves are about one-tenth the length of regular radio waves, they could design the chip to be barely greater than a square millimeter.

It is possible to incorporate the wake-up receiver into microbots for monitoring environmental changes in locations that are either hazardous or too small for other robots to reach. As the device operates on terahertz frequencies, it is possible to use them in emerging applications like radio networks that operate as field-deployable swarms for collecting localized data.

Using terahertz frequencies, the researchers could make antennas the size of a few hundred micrometers on either side. The implication of such small-size antennas is that it is possible to integrate them on the chip, thereby creating a totally integrated solution. Ultimately, the researchers could build a wake-up receiver tiny enough to attach to tiny radios or sensors.

On the electromagnetic spectrum, terahertz waves exist between infrared light and microwaves. At very high frequencies, they travel much quicker than radio waves can. Terahertz waves, also known as pencil beams, travel in a rather direct path as compared to other signals, making them more secure.

However, terahertz receivers often multiply their signal by another signal so that they can alter their frequency. This process is termed frequency mixing or modulation, and it consumes a huge amount of power. The researchers at MIT used a pair of tiny transistors as antennas for detecting terahertz waves. This method of detecting consumes very little power, as it does not involve frequency mixing.

Even when they placed both antennas on the chip, the MIT wake-up chip was only 1.54 square millimeters and used only 3 microwatts to operate. The presence of two antennas maximizes its performance and makes it more sensitive to receiving signals. Once it detects the terahertz signal, it converts the analog signal into digital data for processing. The received signal contains a token, which, if it matches the wake-up receiver’s token, will activate the device.

Wireless Chips for Internet of Things

TI® or Texas Instruments® has announced a new family of companion integrated circuits for SimpleLink®. According to TI®, these offer BLE or Bluetooth 5.3 Low Energy and Wi-Fi 6. The specialty of these chips is they provide connectivity in any type of environment, even when the temperature is over 220 °F (104.44 °C).

Industrial designs such as electric vehicle charging systems operating in the outdoors and sometimes hard-to-access environments is a challenging and expensive options for designers. Under such circumstances, the new SimpleLink® family of Wi-Fi devices from TI® is significantly simpler to install, and more affordable to implement, than ever before.

The SimpleLink® family consists of two chips, differentiated by their functionality. These are the CC3300 and the CC3301. While the lower-cost CC3300 offers Wi-Fi 6 connectivity alone, the other chip, the CC3301 adds the BLE or Bluetooth 5.3 Low Energy support. Both the ICs require pairing with a host microcontroller. This is a departure from TI®’s earlier SimpleLink® designs that combine a microcontroller and the radio. Significantly, there is no vendor tie-in, as both chips can work seamlessly with many types of controllers and processors from TI® and brands other than TI® that support real-time or Linux operating systems.

TI® is offering the devices in a QFN or quad flat no-lead package. Later in the year, TI® plans on introducing pin-compatible CC3xx variants that will add dual-band Wi-Fi connectivity, like 2.4 GHz and 5 GHz. At present, TI®® is also offering the BP-CC3301, an evaluation board.

With a SimpleLink® CC3301, it is easy to add BLE and Wi-Fi 6 connectivity to devices. It offers affordable, secure, and reliable connectivity in embedded applications. All it needs is a MCU host running RTOS, or a processor host running Linux. The BP-CC3301 is a test and development board from TI that the user can easily connect to any TI® Launchpad development kit or to a processor board, thereby enabling rapid software development. 

The user can use the kit in three configurations. One, for MCU and RTOS evaluation they can use the BP-CC3301 and LaunchPad with the MCU like the LP-AM243 running TCP/IP. Two, for processor and Linux evaluation, they can use the BP-CC3301 along with the BP-CC33-BBB-ADAPT and the BEAGLE-BONE-BLACK. Third, for RF testing using PC Tools, they can use the BP-CC3301 and the LP-XDS110. Additionally, the user can also wire the BP-CC3301 to any other RTOS or Linux host board that is also running the TCP/IP stack.

The BP-CC3301 has many useful features. It offers a companion IC providing Wi-Fi 6 and BLE in a QFN package. It has a BoosterPack plug-in module header or a 2×20 pin stackable connector to connect to plug-in modules of BoosterPack or other TIR LaunchPad development kits. The development kit comes with an on-the-board chip antenna with an option for testing based on SMA/U.FL. The kit also provides an SWD type interface for RF testing and standalone operation.

TI® has designed the development kit to accept power from a connected LaunchPad® kit. However, some LaunchPad® kits cannot supply the peak current requirement when the Wi-Fi 6 is operating. In such cases, the user can provide additional power from the USB connector.

Difference Between IoT and Embedded Systems

Today, we are accustomed to using many IoT or Internet of Things and embedded systems every day. But just a decade ago, very few people had smartphones. Innovations and technological advancements have changed that—ushering in an era of the smart revolution almost globally. With the advent of the 4th Industrial Revolution and the revolutionary use of IoT equipment, several million devices link to the internet and cloud services. We can easily connect to the world around us, mainly due to IoT connectivity along with the evolution of regular gadgets. Many new equipment and devices now come inbuilt with IoT technologies, and these include not only personal fitness devices, but also kitchen items, home heating systems, and medical equipment.

Embedded systems typically comprise a small computer integrated into a mechanical or electrical system. Some examples of such devices include electric bikes, washing machines, home internet routers, and heart monitors. Each of these devices comes with an inbuilt computer that serves a specific purpose. Forming the brain of the device, the computers may have one or more microprocessors. For instance, a smartphone consists of many embedded systems interconnected to function simultaneously. So far, embedded systems hardly ever connect to larger networks such as the Internet. Most still use antiquated connection standards such as the RS-232 to interconnect to other embedded systems. These protocols are usually plagued with bandwidth and speed constraints. In comparison, modern communication protocol standards for embedded systems are much faster and support higher bandwidth. Many also support wireless connectivity. All in all, modern embedded systems are more sophisticated than before.

IoT devices, on the other hand, are rather pieces of hardware. They can be machines, appliances, gadgets, actuators, or sensors. Their main function is to transfer data over networks such as the Internet. The design of most IoT devices allows them to be useful for specific purposes. It is possible to integrate IoT devices into various appliances, including industrial machinery, medical equipment, environmental sensors, and mobile systems. There are IoT embedded systems also, and they are embedded systems that connect to the internet or other networks like home networks. Most are capable of carrying out tasks beyond the capabilities of the individual system. Connectivity allows them to perform functions that were not possible earlier.

Sensors effectively behave as the Internet of Things or IoT devices when they can transmit data over networks, including the Internet. It is possible for an embedded system to be enhanced with IoT capabilities by incorporating an IoT module. The basic IoT ecosystem roots still rely heavily on embedded systems. It is possible to gauge the importance of embedded systems within the IoT realm by the fact that embedded systems support much of the functionality of IoT devices.

Although a network, such as the Internet, is a necessary medium for transmitting data to and from IoT devices to their cloud services, embedded systems help in the actual collection, rationalization, interpretation, and transmission of the data from the sensor. Embedded systems also help interface the data with online services, smartphone applications, and nearby computers. In this chain, the numerous sensors that actually collect real-world data, remain the most important link.

5G Modem for IoT and Wearable Devices

Although yet to become a commonplace scenario, we have been seeing and hearing about 5G quite often nowadays. For the most part, IoT devices and wearables are still in the realm of 4G LTE, while the rest of the industry has surged ahead. Now, Qualcomm is set to change that with the introduction of its Snapdragon X35 modem. With their new modem, Qualcomm aims to provide 5G support to these small devices. They are calling this technology 5G NR-Light, because of its reduced capability. According to the manufacturers, X35 modems will have a maximum downlink speed of around 220 Mbps and an uplink speed of around 100 Mbps.

Qualcomm claims their Snapdragon X35 will bring several breakthroughs in the world of 5G. Not only is the design of the world’s first 5G NR-Light modem cost-effective, but its streamlined form factor also leads to power efficiency. In addition, the company has designed the modem with optimized thermal performance. The company expects the Snapdragon X35 to power the next generation of intelligent connected edge devices while empowering an entire range of users. The company is eagerly waiting to work with industry leaders in unified 5G platforms and unleash the possibilities.

Although featuring a tiny form factor, NR-Light is mighty in performance. It features all the good aspects of 5G, starting from spectral efficiency and the ability to access new sub-6 GHz bands. High-end wearable devices, while incorporating the Snapdragon X35 modem, can communicate at the high speeds that 5G offers. In the industrial context, many IoT devices will be able to incorporate the X35 modem to improve their performance. The company is aiming its new modem at devices like Chromebooks, router products, low-end PCs, and many more. Another good feature is the new modem does not need an additional Qualcomm SoC to make it function.

To make it compatible with existing devices, Qualcomm has designed the Snapdragon X35 to support 4G LTE as well, as a fallback option. Even with such powerful features and working at such high speeds, the new modem consumes the lowest power of all the modems the company has manufactured so far. Although many other OEMs are showing a lot of interest, the first device to use this modem will emerge only in the first half of 2024. According to Qualcomm, the price of the Snapdragon X35 5G NR-Light modem will be around half that of its counterpart, the Snapdragon X55 modem.

Qualcomm has released more interesting features about their new modem. According to them, the Snapdragon X35 modem has the same interfaces as its predecessor LTE modems. This information is of vital importance for existing consumers with older designs. At least in theory, they can integrate the new modem in their designs with ease and avail the capabilities of 5G instantly.

Qualcomm has one more trick up its sleeve. They have announced another new modem, the Snapdragon X32, in addition to the Snapdragon X35 modem. They have designed the X32 modem as a modem-to-antenna solution suitable for use on lower-cost devices that work on NR-Light.

Batteryless Microcontrollers for IoT

Ten years ago, IBM predicted the world will have one trillion connected devices by 2015. However, as 2015 rolled by, the world had yet to reach even 100 billion connected devices. The major problem—a trillion sensors mean at least a trillion batteries.

Although a significant problem, it did not make economic sense. Everyone was expecting the IoT technology to bring on a large value-addition, that of range. They expected IoT to bring the Internet to remote corners of the world, thereby interconnecting vast areas with IoT sensors and their information-gathering powers. Therefore, the internet and its incredible power would be visible in various places like large farms, factories, lumbering operations, construction sites, and mining operations, with enormous coverage and decentralized operations.

Typically, sensors collect data for IoT networks, which distribute it for processing and analysis. If sensors require batteries for operation, it places a severe restriction on the number of sensors that a network can use. This, in turn, goes on to defeat the entire point of having IoT in the first place.

For instance, consider a large-scale agricultural operation. IoT can bring major value addition to such a business through its coverage. By deploying multiple sensors across the entire operation, it is possible to access valuable information capable of generating highly actionable insights. Now consider the recurring cost of replacing or maintaining the huge number of batteries every year—making the proposition less compelling very quickly.

Not only would the resources, cost, and manpower, for replacing or maintaining the batteries on all the sensors be astronomical, but they would also easily surpass any possible savings that the system would likely bring.

According to an estimate, a trillion sensors would need 275 million battery replacements every day. This, assuming every battery deployed in the IoT network reached its claimed life of ten years. The next hurdle is even worse—discarded batteries poisoning the environment.

The above problem has resulted in sensors and microcontrollers getting more efficient and cheap. Modern sensors are now extremely reliable, consuming minuscule amounts of energy. Batteries have also improved, with the industry exhibiting robust batteries with higher energy density and longer life. However, the future of microcontrollers and IoT sensors needed to be batteryless. This led scientists and engineers to develop energy harvesting technologies that could eliminate the battery from IoT altogether. 

Energy harvesting is the technique of scavenging power from the surroundings, which has many forms of it—heat energy, electromagnetic energy, vibrational energy, and so on.

Considering that modern microcontrollers for IoT need only a few millivolts to operate, many are developing energy harvesting technologies as a potential power solution that can replace batteries.

This has given rise to self-powered microcontrollers in the market. For these MCUs, batteries impose no restrictions, as they harness their own energy from the environment. They use a number of harvesting technologies based on various power sources and kinds of materials—piezoelectricity, triboelectricity, and RF energy harvesting being the leading contenders in the category. Therefore, with energy harvesting powering microcontrollers, IoT can once again begin to chase the magic figure of one trillion interconnected devices.