Increasing driver safety can be done in numerous ways. Clearing the lens of headlights improves lighting. The increasing use of sensors used for driving safety requires technology to clear the glass in front of the sensors.
However, there has not been a specific technology designed for these tasks. CHASM Advanced Materials has developed AgeNT, a new category of transparent conductive materials known as CNT Hybrids as a solution for touch screens in harsh environments. The CNT Hybrids are a patented combination of silver nanowire (AgNW) and carbon nanotubes (CNTs). CHASM works with companies to implement their custom transparent heaters using its materials.
These CNT Hybrids are already on the road, and the approach may also be useful for clearing the way for sensors to gather their data.
“The operational and safety standards used in the automotive industry are very demanding as consumer safety is paramount,” said Ken Klapproth, VP of marketing for CHASM. “This results in lengthy qualification processes of multiple years. CHASM CNT Hybrid heaters are currently navigating that process for many automotive brands and we expect new product introductions in 2022 and 2023. CHASM heaters are in production keeping touch screens operational on industrial equipment around the globe.”
Unlike other commercially available solutions, CNT Hybrids are both transparent and flexible so they are ideal in any heating application where a consistent, even heat source is either required or desired but – more importantly – must have no visible heating element. Klapproth noted that CHASM is currently working with several automotive OEMs, Tier 1 and Tier 2 suppliers on a variety of applications.
“Modern LED headlamps feature sculpted, 3D designs where styling is as important as function,” he said. “Engineers are looking for a solution that doesn’t negatively impact light output and can keep headlamps clear of ice and snow. LEDs generate little heat and modern headlamps can also house collision avoidance safety sensors such as radar and LiDAR – when they ice over, these systems can go offline. Another important automotive application is windshield heaters to keep optical cameras clear of ice and snow as well.”
Driver-assist technologies such as adaptive cruise control, collision avoidance, automatic braking and even lane assist use optical cameras to assess constantly changing surroundings. These optical systems are also used in autonomous driving platforms.
“Keeping them operational and reliable requires heating and traditional microwire heating elements would block their view,” said Klapproth. “Industrial equipment manufacturers or self-service kiosk manufactures can keep their touch screens operational in harsh/inclement environments with a transparent heater. Window manufacturers or manufactures of commercial refrigeration devices desire transparent heaters to keep the view free of condensation. This way, the glass door on the supermarket refrigerator won’t fog over when you reach for your favorite ice cream.”
Unlike other heating technologies that use discrete resistive elements like a wire or a printed conductor that concentrates the heat then relies on conduction to spread to surrounding areas, transparent heaters deliver continuous, consistent heat. It heats up and maintains heat evenly distributed across the entire surface. Transparent heaters made from CNT Hybrids are flexible and formable, so they can even be applied to three-dimensionally shaped interior surfaces in electric automobiles putting the heated surface as close to the passenger as possible.
Klapproth noted that finding the optimal combination of materials for the transparent CNT Hybrid heaters required some development, but the continuing challenge is in testing and qualifying the connectors in use across industries.
“While the heating element is fairly consistent from automotive to industrial electronics, the preferred connectors to electrical sources and the available voltage/current can vary widely,” he added. “We have yet to find a connector we couldn’t accommodate, but each requires a bit of creative engineering.”
Klapproth anticipates transparent heaters being included in more vehicles or even becoming standard features in the future.
“From the interactions we’ve had with multiple tiers in the automotive industry, there appears to be keen interest in being the first to offer a proven solution for transparent heating in a variety of applications,” Klapproth added. “Introduction will likely be first in a luxury brand, but will likely spread quickly throughout a brand’s models. Just as it’s difficult to find – or even remember – a car model today that doesn’t have power windows, in a few short years you’ll be thinking the same about transparent CNT Hybrid heaters.”
