A revolutionary energy harvesting technology that turns ambient radio frequency (RF) waves (RF) into usable electricity to charge low power electronic devices, was launched yesterday (30 September 2015) by Lord Drayson, CEO and chairman of Drayson Technologies at the Royal Institution in London.
The patented technology was developed by an international team from Drayson Technologies and Imperial College London. Drayson Technologies claims to be the first to market with this technology, which is commercially available now for license to the international developer and business communities.
Freevolt is able to pick up unused electro-magnetic energy from sources such as mobile cellular networks, Wi-Fi and digital television transmissions without the need for charging by cable or a dedicated transmitter. Freevolt can harvest this energy without interrupting the data signal. The type of devices it is able to power will depend the device’s energy budget, form factor and the amount of available ambient radio energy.
Three breakthroughs had to be made to develop Freevolt. “Companies have been researching how to harvest energy from Wi-Fi, cellular and broadcast networks for many years,” said Lord Drayson.
“But it is difficult, because there is only a small amount of energy to harvest and achieving the right level of rectifying efficiency has been the issue – up until now. With Freevolt, we have created something special. For the first time, we have solved the problem of harvesting usable energy from a small RF signal.”
Drayson Technologies has got round this problem be enabling Freevolt to harvest enough usable energy from multiple frequency RF signals at the same time to power a low energy, commercially available device. The solution involves the creation of a multiband antenna with a wide angle able to absorb energy from multiple RF signals at almost any orientation simultaneously.
The second key development is a slim, lightweight, low-cost rectifier, which turns the harvested energy into a DC output. The antenna and rectifier are combined to form a highly efficient rectenna.
The third breakthrough development is a power management module with maximum power point tracking. This manages the output of the rectenna enabling it to home on the strongest RF sources within a constantly changing RF environment; it then boosts the voltage provided.
Drayson describes what Freevolt offers as ‘perpetual power’, as the low energy devices it powers never need to be plugged in or have their batteries changed. The energy can be stored in many types of energy storage devices from Li-Ion batteries to grapheme super-capacitors or charge a low cost printable battery.
The amount of energy Freevolt can deliver depends on the size of the antenna. A credit card sized Freevolt rectenna can deliver up to 100 μW in a typical high-energy environment such as the home or office. It could not be used to charge something like a smartphone, however. Drayson said that even remote sensors out in the countryside can harvest enough energy from digital terrestrial TV signals to power low energy devices.
Freevolt is easily scalable as two or more rectennas can be combined in an array to harvest more energy – up to 3mW, for example, for applications that require a greater energy budget. Drayson speculated that it would be entirely possible to coat the walls of a house with Freevolt devices.
Drayson said the range of possible applications is endless, but Internet of Things (IoT) sensors, beacons and wearables, such as fitness bands, clothing and medical garments, are obvious markets. In fact, the company has developed a commercially available personal air pollution sensor called CleanSpace Tag to help illustrate the kind of device Freevolt is appropriate for.
CleanSpace Tag air sensor
The idea behind the CleanSpace Tag air sensor (pictured above), which is the size of a smartphone, is to create a crowd-sourced network of personal air sensors, initially across the UK and then expanding to major cities across the world, which will all be powered by Freevolt.
The Tag is backed by CleanSpace, a technology-enabled social movement to improve the air we breathe, designed and built by Drayson Technologies and launched to the public in 2015.
It works by monitoring air pollution to show people exactly what they’re breathing, wherever they are – while commuting, exercising or taking the kids to school.
Drayson said that environmental experts advised monitoring carbon monoxide as the key air pollution indicator. This is because carbon monoxide, being a product of incomplete combustion, provides a good representation of overall air quality comprising many other pollutants, including particulate matter and nitrogen dioxide.
Users download an app onto their smartphone and the data from the Tag is transferred by Bluetooth low energy to the mobile, where it is recorded. The data can then be displayed to show users the cleanest routes and areas available, and records when they are making clean travel choices. The data can then be anonymised, sent to the Cloud and merged with current air pollution data from static sensors installed around the UK.
This is then fed into the CleanSpace app, giving all users more detailed hyper-local pollution data so they can choose cleaner routes that avoid exposure to harmful air. This allows the population as a whole to work together to reduce the personal health risks of air pollution, and help reduce the wider problem at the same time.
In an effort to get people to buy the sensor and incentivise them to keep using it, CleanSpace has also partnered with a number of brands and companies that share its vision to offer people rewards for making cleaner journeys by foot or by bike. Rewards start small (a coffee, for example) and increase in value the more clean miles users rack up.
Available from today through Crowdfunder: www.crowdfunder.co.uk/cleanspace, the new CleanSpace Tag syncs with the CleanSpace app to monitor users’ pollution exposure in real-time. Because it never needs to be recharged, people will always know the quality of the air they’re breathing.
Lord Drayson said: “Recent news reinforces what many of us have been saying for a long time – air pollution is a critical concern to every individual’s health. Now, more than ever, people want to understand the state of the air around them.
“Information on air pollution is available, but many people don’t know how to access or use it. People are demanding more immediate and localised data on the quality of air that surrounds them. They will trust information that they collect and interpret themselves; this is what CleanSpace, and the CleanSpace Tag, provides them.”
Drayson added that if the CleanSpace Tag is widely adopted then CleanSpace has the potential to build the world’s most detailed map of air pollution and use that data to effect real change.
The CleanSpace Tag will not only provide users with more granular data, but also give a reading of air pollution levels at the height at which people actually breathe, improving the UK’s computer models for predicting and estimating air pollution.
CleanSpace Tags will initially retail via Crowdfunder for £65 each which includes a £5 donation to a CleanSpace charity partner - British Lung Foundation, EarthWatch or Sustrans.
For more information on Freevolt please visit: www.getfreevolt.com
For more information on CleanSpace please visit: www.ourcleanspace.com