The early tires were rather primitive—just solid rubber strips. Then, Charles Goodyear’s invention of vulcanized rubber allowed Robert Thomson to patent the vulcanized rubber pneumatic tire in 1846, four decades before the advent of motor vehicles and his lost patent battle with John Dunlop. Detachable tires swiftly followed, thanks to the Michelin brothers, and by the 1970s, the pneumatic radial tire with a tread—still used on most cars today—became standard.
Besides some unusual tire innovations along the way, today’s automotive manufacturers take into consideration not only safety, durability, and performance, but sustainability as well. It sets the stage for groundbreaking progress in tire technologies.
Today’s tire technologies
Take tire noise, for instance. There are two main causes of tire noise. One of them is pattern noise, a sound of inconveniently high frequencies comparable to human speech, caused by the constant release of air bubbles trapped in the tread. The other is cavity noise, caused by air ‘bouncing’ inside the tire and compressing against the wheel. Naturally, with the invention of the more subtle electric motors, the demand for quieter tires increased, too.
Released in March 2019, Bridgestone’s QuietTrack tire has multiple short diagonal grooves leading to the tire’s shoulder, allowing air to escape rather than compress as the tire revolves (Figure 1). The grooves are cut in three different widths to interfere with each other’s noise, reducing it at human speech frequencies. Additionally, QuietTrack tires have thin longitudinal channels with millimeter-high serrations in the trough to break up high frequency sounds. It’s handily turned out to improve traction in snow and on wet surfaces.
Figure 1. QuietTrack tires dampen the annoying noise, a key feature for electric vehicles (EVs) whose lack of revving engines makes the rubber’s sound more noticeable. (Source: Bridgestone)
This tire contains Contiseal, a viscous sealant layer applied to the inside of the tread, which can leak out to seal as much as 80% of a puncture. Suitable for punctures of up to 5 mm in diameter, the technology reduces the risk of a flat tire and roadside tire change.
Tomorrow’s tire technologies
Introduced in 2017, Goodyear’s Eagle 350 Urban is a spherical concept tire that enables a vehicle to move in any direction. The built-in artificial intelligence (AI) links to sensors on the exterior of the tire detect different road surfaces and driving conditions to adapt the tire shape and tread using actuators. Aside from transmitting data to improve braking, handling, and efficiency, the Eagle 350 Urban facilitates the mending process upon puncture.
With a unique open structure, the non-pneumatic Oxygene tire—not supported by air pressure—is 3D-printed from recycled tire dust, and carries living moss in its sidewall. It absorbs water from the road and CO2 from the air to feed the moss, stimulating photosynthesis and oxygen production. It also uses Li-Fi, a mobile wireless technology based on light, to connect to the Internet of Things (IoT) infrastructure for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) data exchange.
Now, in 2020, the non-pneumatic reCharge tire implements capsules that hold a biodegradable liquid compound used for tread regeneration. AI allows the compound to be customized to the driver profile and the tire to adapt to road conditions.
Pirelli’s Cyber tire is the first intelligent tire to demonstrably transmit information via the 5G network, facilitating communication with the vehicle, driver, and wider roadway infrastructure (Figure 2).
Figure 2. Pirelli claims to be the first tire company to have interacted with the 5G network. (Source: Pirelli)
Next, Michelin’s Uptis tires may be available as early as 2024. Its ‘assembled airless wheel structure technology’ eliminates the risk of punctures, blow-outs, and flat tires. By reducing the use of raw materials, tire scrappage, and the need for spare tires, the Uptis tires will minimize resource use as well as waste.
For those interested in more concrete examples, Goodyear’s tires for Tesla are fitted with specialized noise reduction foam—if you enjoy the silence—while the tires for Citroen’s autonomous 19_19 concept EV are designed to stiffen in dry conditions and soften when exposed to moisture.
The connected road ahead
Connectivity will be huge, with 5G and IoT used to transmit information from tires to increase safety and performance in both advanced driver assistance systems (ADAS) and autonomous vehicle arenas. Case in point: Goodyear’s AndGo platform will use predictive software to connect fleets with its service network.
3D-printing of tires, use of recycled and eco-friendly materials, and reduction in tire wear and scrappage will all be key components in tire manufacturers’ sustainability efforts. The more durable non-pneumatic tires and 2-in-1 tire-and-wheel technologies also promise increased safety and reduced maintenance, particularly vital for driverless cars.
After decades of tire status quo, it seems that everything is set to change.
>> This article was originally published on our sister site, EDN.
|Giles Kirkland is a car expert who regularly contributes to automotive and technology publications.|