A Solution for Ice-Free Sensors

Canatu’s carbon nanobots keep critical sensor surfaces – and LED headlamps – clean in sub-freezing weather.

Sensor surfaces that are exposed to weather need to be kept clean so that ADAS and autonomous driving systems can function safely. Ice build-up in cold conditions is of particular concern, but Canatu thinks it has a solution. The Finland-based technology company has developed a transparent, highly conductive heater element that does not require metallic wires to be placed in front of the sensor.

These elements keep lidar sensors and cameras ice-free, thanks to carbon nanobot (CNB) heaters. "If there is ice on top of your critical sensors, you're not able to drive safely," said Samuli Kohonen, Canatu's VP of sales. "Our heating technology can keep your sensors clean in every weather and creates even and fast de-icing in extreme conditions."

Canatu's CNB heaters are made up of a resistive carbon nanobot heater surface with electrodes on the side, covered by a lens (which can be made transparent) containing a thermistor temperature sensor. Exact specifications on how warm the sensors get varies depending on how the heater is shaped. The company claims an A5-sized heater with 2.25-mm (.088-in) thick cover can warm the surface by 10 deg. C in 5.7 sec., keeping the surface above freezing.

Canatu creates the nanobots by feeding a proprietary blend of carbon gases into reactors. The nanobots then are deposited onto a plastic substrate. The plastic can be molded into different 3D shapes with the nanobot-covered film either integrated in the plastic sensor covers or laminated behind glass for applications such as side mirrors or entire windshields. The production process is patented and protected, and Canatu's modular production system could be scaled up and started almost anywhere, Kohonen said.

EVs can make particularly good use of CNB heaters because they are "more effective from a power- consumption perspective because we are bringing heat exactly to the areas where it's needed," Kohonen said. Headlamp enclosures can benefit from the CNB heaters as well. "Traditionally, de-icing headlights wasn't a problem because of the heat from the lightbulbs," he explained. "Now, with everybody moving to LED headlamps, there starts to be problems with ice on the headlamps."

Canatu's CNB heaters are not yet available in production vehicles, but Kohonen said "several" of its customers are road-testing the technology around the world. In late 2018, Canatu signed a non-exclusive licensing agreement with Denso to build CNB heaters for the Japanese supplier. "It's a pretty nice deal for us because it's enabling our technology to spread to areas where we are maybe not able to go alone," Kohonen said. In October 2019, Canatu announced it had raised 15 million euros in capital from Denso, 3M Ventures and Faurecia, and has since opened a new factory in Vantaa, Finland.