Power Harvesting: Using NFC to Design Affordable and Resource-Efficient Devices

Near-Field Communication (NFC) technology came to market as an efficient, secure data transfer protocol which has enabled the contactless payment lifestyle. But like most enduring disruptive technologies, it has continued to evolve beyond this initial use case. The first installment in our series on wireless power established how NFC technology allows product designers to create intuitive solutions to charge devices such as smartwatches, headphones, wearables and more without the need for cables. But what about devices with no battery at all?

As the IoT continues to expand, so does the number of use cases that require low-power IoT devices. Many of these represent innovative solutions that go well beyond the parameters of traditional connected devices. However, for many of these devices, it is not practical or economically viable for them to have the capacity to store their own power. So how can product designers create a device that “activates" without storing its own power?

Enter power harvesting.

What is Power Harvesting? —and Why is it Important?

All NFC solutions work in the same fundamental way. Two devices – a tag and a receiver – interact through a radio frequency (RF) field created by the NFC tag. The receiving device contains an antenna that is triggered when it enters the RF field of the tag, facilitating the transfer of data.

However, data is not the only thing that can be transferred over the RF field. Product designers can integrate an NFC Forum Wireless Charging complaint power harvesting chip that does not require a battery or other any other form of power supply. This means that energy could be transferred from something like a mobile phone to the battery-less device which can then be used to power the product for a brief period of time.

From both a cost and an environmental sustainability perspective, eliminating the need for a battery or charging cable offers product designers and end users significant benefits. Such charging devices and batteries are often made from materials such as zinc, lithium, or potassium, and the extraction of these materials can have catastrophic impacts on the environment. Therefore, if designers can deploy a solution that leverages the battery power of another device, the volume of these resources that need extracting is reduced significantly, saving time, money, and the environment.

How Can Power Harvesting Be Used?

According to a 2021 report by Markets and Markets, the global energy harvesting system market size is projected to reach $701 million by 2026, growing at a compound annual growth rate of over 8%. While NFC wireless power delivers the convenience of cable-free charging to smaller form factor products and devices, NFC Forum compliant power harvesting allows devices to go a step further by eliminating the need for batteries, resulting in the tremendous potential to drive the development of multiple new offerings.

Smart padlocks are one of the most advanced use cases of power harvesting currently in production. A user can simply hold their mobile phone within range of the lock to activate it, allowing seamless, secure access with just a tap. Furthermore, by enabling key storage on a user’s phone, NFC technology frees the lock manufacturer from the responsibility of storing all credentials in a centralized database. This greatly mitigates the risk of cyberattacks against the lock manufacturer since, even in the event of a breech, hackers will not be able to access individual locks. The end product is more secure for both users and manufacturers.

Similar innovative use cases are beginning to emerge across other verticals. Clothing brand Hugo Boss recently announced that it will integrate NFC tags into a range of hats that will allow the wearer to create non-fungible token (NFT) digital copies that can be used to dress metaverse avatars. By using NFC Forum complaint power harvesting and eliminating the need for a battery or power supply to operate, these uses are far more cost- and resource-efficient.

NFC Forum’s Wireless Power Specification and Power Harvesting

The NFC Forum wireless power specification offers product designers the solution they need to create innovative power-harvesting devices. Adherence with this specification facilitates the efficient transfer of power while also delivering the high data speeds and enhanced security that the ecosystem has long enjoyed from NFC-based solutions.

NFC is already a key element in product design and has proven its capabilities within the payments and internet connectivity ecosystems. This means that the investment in NFC to integrate wireless charging and power harvesting is minimal. Power harvesting represents a significant opportunity for product designers to dematerialize many resource-constrained—but still power-dependent—connected devices. By utilizing NFC power harvesting, these devices can be made without batteries and charging cables, cutting down the environmental impact of creating the device and lowering the cost of ownership for consumers.

If you would like to learn more about NFC Wireless Power for designing personal devices, you can read part one of our wireless charging blog series here.

You can also watch the recording of our webinar on wireless power. The session provides insights from a panel of experts from Huawei, Infineon, NuCurrent, NXP, Panthronics, STMicroelectronics, Zebra Technologies and Wired & Wireless Technologies Ltd (WAWT).