Tyres: The stealthy microplastic pollution we never thought about.

Microplastics are an emerging health and environmental concern. These particles are commonly associated with single-use plastics, microfibres, and microbeads. However, the second-largest microplastic contributor comes from a source we never thought about: Tyres.

Today, half a million tons of tyre particles are produced annually in Europe alone, from vehicles accelerating, braking and cornering. Tyre wear pollution is washed into our waterways affecting marine life and entering our food chain. These particles are also small enough to become airborne and have adverse health effects on our lungs and heart. They already account for almost 50% of PM2.5 pollution from road transport and will account for 10% of all PM2.5 emissions by 2030. As we move towards electric vehicles, tailpipe emissions are set to reduce but tyre emissions are projected to increase due to the added battery weight and torque. The future of vehicle pollution will not come from tailpipes, but from tyres. It is crucial to consider the implications of tyre wear, so we are not replacing one pollution source with another.

The Tyre Collective aims to mitigate emissions by capturing them at the source, stopping them from entering our environment to ensure clean air, and safeguarding our health. We discovered these particles are charged from friction as they fly off tyres. Our patent-pending technology uses electrostatics to capture tyre wear right at the wheel. The particulates are gathered in a removable storage unit. Once collected, these fragments are processed and can be reused in a variety of applications, creating a closed-loop system.

This is a complex issue and we cannot solve it alone. The name, The Tyre Collective, reflects our ethos of bringing people together; across disciplines and industries to truly make an impact. Our solution is a result of collaboration with experts from Aerodynamics, Material Science and Chemical Engineering, facilitated by design. It moves beyond concept by providing a tested solution backed by research and driven by a service model. For decades, tyre design has been focused on durability and efficiency. Now, we are accounting for their sustainability.

Design Challenge Tyres wear down every time we accelerate, brake and corner. An estimated 3 billion tyres were sold across the world in 2019. To meet this demand, modern tyres are manufactured with increasing ratios of plastics along with synthetic rubber, silica, and carbon black. Natural rubber is only a small part of the complex materials that makes a tyre. The composition of tyres have become more complex over the past 150 years and a sustainable, wear-free wheels have remained as concepts. How might we tackle this invisible source of pollution and derive value from it?

How does it work? In our research phase we explored numerous collection methods like vacuuming, adhesion and filters to capture tyre wear. What started with rubbing a balloon against a sweater, eventually led to the creation of our device, TC-02. It consists of a charged array of metallic plates, to direct and attract these particles. We tested different configurations to maximize collection surface area. Our design harnesses the spin of the wheel as a power source. TC-02 is only activated under dry conditions, when a vehicle accelerates, braking, and corners, reducing the amount of foreign particles collected and improving energy efficiency.

Where is it located? We worked closely with the Imperial College Department of Aeronautics, to position the device as close as possible to the contact patch between the road and tyre. It takes advantage of the airflow around a spinning tyre, it is more effective than outdoor HEPA filters, and consumes less energy than vacuuming. The device is mounted onto the steering knuckle, adaptable to different vehicles, and free to move with the suspension and when turning. Currently, our device collects 60% of all airborne particles on our test rig.

How do we create value? The captured particles are stored in a removable cartridge on the device, which is emptied and replaced while servicing the vehicle. Fine tyre dust is extracted from the captured particles using simple density separation techniques. Once separated we can reuse these particles in a variety of applications, creating a closed loop system and a potential secondary market. Conversations with material experts from Imperial College Department of Civil Engineering confirmed that particles under 50 microns are small enough to be reused in new tyre production. Other creative applications include 3D printing, soundproofing, and inks and dyes.

Awareness, Action and Impact There are three main sources of vehicle emissions: tailpipe, brake wear, and tyre wear. Electric Vehicles and regenerative braking will dramatically reduce tailpipe emissions and brake wear, leaving only tyre wear. We are the first solution considering tyre wear collecting at source, and will be the first to break into the market. Our solution hinges between legislation and adoption for it to have a lasting impact. In response, we designed a two fold strategy of Awareness and Action.

Awareness involves working with legislators and nonprofits to raise awareness and participate in policy making. While regulations on non-exhaust emissions are in progress, clean air in cities remains a top priority. We are working with the UK Environment Agency to raise awareness of the effects of PM2.5 and tyre wear, and have received a letter of interest to support our project.

For Action, we envision our technology becoming a worldwide standard, licensed to all vehicles. To achieve this, we are targeting public transport, since buses are amongst the largest contributors due to their weight. In the current phase, we have identified our beachhead market as Transport for London's 9000 bus fleet as they have regular maintenance schedules for our collection process. We have already begun conversations with TFL to make this a reality.

We envision our device as the "catalytic converter" for tyre wear, a new standard for vehicles worldwide. In contribution to the current research conducted globally, we advocate for stringent non-exhaust emission standards, and aim to bring tyre emissions down by 2030. In our fight against air pollution, tyres have largely been ignored. Now, together, we can save our air from tyre wear!