Until now, classic rubber and plastic products in cars have only fulfilled simple mechanical tasks – keeping air in the tyre, transferring coolants across the vehicle’s machinery and so on. If Tim Wolfer, who coordinates research projects for functional printing processes at the Freiburg site of the automotive supplier Continental, has his way, these components will in future have their own intelligent sensors and actuators and thus be fed into the digital processing of data in the car.
The focus of the research projects he coordinates is on the integration of intelligent systems and networks. “In particular, we are looking at the interface of components made of elastomers and the integration of electronics,” says Wolfer.
One of Wolfer’s most important projects is the “sensIC” project: Integrated sensor technology is used on the basis of printed electronics in hose lines for electric vehicles. Specifically, hoses for the thermal management of vehicle batteries are equipped with integrated temperature sensors. Continental is bundling such research projects in the printing technology centre in Freiburg; sensIC will run for three years. The German Federal Ministry of Education and Research is supporting the project proportionally with €2.9 million.
Continental expects a lot from sensIC – above all, a wide range of applications for the technology and lower costs in production. “Printed electronics we can theoretically use everywhere. The product range is virtually infinite and perfectly tailored to Continental’s strategy: making products intelligent and developing new business models and mobility services from them,” says Wolfer. “Hoses are just one example. But if it works there, then also in air springs, belts, conveyor belts and tyres, for example.”
The roots of this technology go back to 2018, when Continental demonstrated printed electronic components on rubber substrates to the public for the first time at the LOPEC trade fair. While it was still a matter of basic technology back then, the company is now much further ahead. Now the aim is to transfer these technologies from laboratory scale to industrial production. “In this respect, the project has lighthouse character for us,” Wolfer emphasises. “We are using highly productive printing processes in this project to manufacture the electrical circuits. These processes promise a very large throughput of processed area at very low cost.” One important condition: The printed electronics integrated into the carrier material must be absolutely safe, because they are to be installed in automobiles and equipment. “Therefore, a special focus in the project is on securing the electronic systems against manipulation and plagiarism,” explains Wolfe. “The systems have an enormous complexity even on a small scale because of the fine and sensitive structures. For example, a specific silicon chip is being designed and produced for us as part of the project. But in the subsequent production in Hamburg, we are then suddenly confronted with challenges such as thermal expansion, solvents, high pressures and high temperatures.”