Wiliot – The Battery-less IoT Device

11-01-2021 |   |  By Robin Mitchell

Recently, Wiliot announced the release of their battery-less IoT device. What is the device capable of, what technological challenges does it face, and how could it change the IoT industry?

Wiliot Announces Battery-less IoT Device

Wiliot, a fabless IoT company, has released their first IoT product, the Wiliot Bluetooth Tag, that integrates all the needed components to create a small, IoT device. However, unlike other IoT devices on the market, the Wiliot does not contain a power source and utilises an antenna to power itself from ambient radio waves.

The device itself is not larger than a postage stamp, and the device is essentially an ARM microcontroller integrating a three-core CPU, RAM, and ROM, which is then connected to a power circuit. According to Wiliot, the device's intention is to be sold at pennies but currently sells for “under a dollar” making the devices somewhat niche. 

Current development is seeing the second version of the Bluetooth tag sold at prices between 10 to 50 cents, and the third version to bring that price down even further to individual pennies. The first version of the device is already being shipped and used, but the devices' real advantages will come when their price drops enough to make them essentially disposable.

What ambient energy does the Wiliot absorb?

The concept of energy harvesters is not new; it is a very common project that many makers like to develop. Energy harvesters are devices that harvest energy from their surrounding environment and convert that energy into electricity for powering circuits.

One of the biggest challenges behind energy harvesters is the very little ambient energy and the power-hungry nature of many circuits. Thus, energy harvester designs can take two approaches; either increase the energy harvested or reduce the circuit's power consumption.

In the case of Wiliot, the energy that is being absorbed is radio waves of all different frequencies including Wi-Fi, 5G, 4G, FM radio etc. The use of three looped antennas allows the Wiliot to absorb this energy efficiently, but this is only half the story. To use this energy, Wiliot also takes advantage of nanowatt ARM CPUs that can use extremely small amounts of power when in sleep mode, and then use a burst mode to process all needed data and transmit, before going back to sleep to charge the energy harvester.

How will Wiliot-like technology change the world?

What started as light bulbs and switches have now become an industry that touches almost all aspects of life. In fact, it is almost impossible to find an industry that is not involved with electronics to some degree.

As electronics becomes smaller and cheaper, it can be integrated on a greater scale. The use of devices such as Wiliot will usher in a new era of disposable electronics. Such technology would allow for easy tracking of shipments such as food and medicine, which has strict environmental requirements.

Smart labels printed onto food could allow customers to see all aspects of the food’s journey, its freshness, and metadata including what specific factories were responsible for the food production, and even the employees on-site during the day of manufacture. 

Battery-less sensors also have the ability to be placed in any remote location and still be able to function. Therefore, remote environments would benefit from the Wiliot, and the use of drones with Bluetooth transceivers could gather data from the sensors as it flies by.

Read More


By Robin Mitchell

Robin Mitchell is an electronic engineer who has been involved in electronics since the age of 13. After completing a BEng at the University of Warwick, Robin moved into the field of online content creation developing articles, news pieces, and projects aimed at professionals and makers alike. Currently, Robin runs a small electronics business, MitchElectronics, which produces educational kits and resources.

Related articles