Trust is key

    The automotive door handle sensor S3. Reliable under all conditions.

    What good is a keyless system if it doesn’t work reliably? That’s the question many angry vehicle owners ask themselves when their door handle sensor fails because rain has caused the door handle sensor to malfunction, yet again. Marquardt has solved this problem! The mechatronics specialist’s Superior Sensor Solution S³ is a sensor that won’t malfunction as a result of water, dirt or ice.


    Capacitive sensors have been around for a while - but not waterproof touch solutions. Marquardt is the first supplier in the market to offer a weatherproof system. Superior Sensor Solution—S³ for short—is our answer to solving a longtime concern that has caused headaches for many car makers. Manufacturers of construction and agricultural machinery, off-roaders, power tools, and kitchen appliances have also struggled with issues caused by moisture, rain, dirt, dust or ice falsely activating conventional sensors. In some cases, it may cause the sensor to stop working all together.

    Johannes Mattes is the systems engineer responsible for developing door handle sensors for Marquardt customers all over the world. He explained what makes these systems fail so regularly: “Most of the human body is actually made of water, and conventional sensors can’t tell the difference between a fingertip and a rain drop. If a door handle is wet or icy, the system will only recognize a capacity change that is similar to the one caused by a human hand.” The result is an annoying and even costly malfunction. For example, drivers caught in the rain may not get into their dry car as quickly as possible. Instead, they are left outside because the keyless sensor fails to unlock the door. By the time the key has been retrieved from a purse or pocket, the driver is soaked —and the manufacturer has yet another unhappy customer. A similar malfunction can become really expensive when it occurs in a drive-thru car wash. The washing roller brushes and water could trip the car into unlocking unintentionally. Furthermore, if the locking system is in summer mode and automatically rolls down the vehicle windows, the resulting damage could be very costly.

    Our solution is a technology that is in tune with its environment.

    Johannes Mattes Systems Engineer at Marquardt

    Marquardt’s latest sensor innovation can help prevent such problems. “Our solution is a technology that is in tune with its environment”, summarized Johannes Mattes regarding the basic idea behind S³. Unlike conventional sensors, S³ measures not only capacity changes, but also, other electrical factors in the immediate environment that change due to water or ice. The system takes these factors into consideration during its evaluation of the signal and adjusts its response accordingly. In other words, S³ can differentiate between a user’s hand and a rain drop. “That allows us to solve all problems caused by water”, explained Johannes Mattes. A recent stress test, conducted by a major auto manufacturer, provided proof that the S3 system works even in extreme conditions when it functioned without a problem in their rain chamber, which simulated an Indian monsoon rainfall. This goes far beyond car door handles. Other vehicle parts such as fuel filler caps, trunk openers, engine hoods and touch pads on the B-pillar also benefit from this technology.

    „The success of the system is also opening doors elsewhere because more and more customers from non-automotive sectors are discovering it.“

    Johannes Mattes and his team are continuously working on broadening the range of applications. Domestic appliance and home automation devices can all be equipped with the technology, for instance extractor hoods, hobs, or control panels on the exterior walls of a building, so can off-road vehicles, construction and agricultural machinery, watercraft, power tools, and high-pressure washers. To make sure that the sensors work in all possible circumstances, the team will simulate a variety of scenarios during development, right down to the last detail. Mattes knows – “Not all water is alike. There is a difference between moisture on a hob coming from a soaked cleaning cloth or a pot of pasta boiling over, or a car getting wet from sleet mixed up with road salt or clean water in the car wash.” A smiling Mattes adds that a lot of imagination is needed to anticipate all sorts of possible scenarios the system may have to deal with: For instance, what happens when a snail crawls over the control panel on the wall of a house, or a wet leaf sticks to it in fall? Will the sensor still work as it should? Marquardt's developers take all these eventualities into account because, after all, only a reliable sensor is a good sensor. And that’s what makes the difference—in any weather and under any circumstances.

    We taught the sensor to distinguish between human and humidity.

    The evolution of the conventional door handle sensor started with a need from the automotive industry. Since then, Marquardt has developed the technology for multiple use cases across various industries. “The success of the S³ system is also opening doors elsewhere because more and more customers from non-automotive sectors are discovering it,” continued Johannes Mattes. “There are virtually no limits to the imagination. The sensor is an option wherever touch solutions are a possibility and water could get to.” S³ can be inserted underneath any closed surface, whether it is plastic, tile, wood, or leather. Regardless of industry or use case, the consumer will always receive a more reliable and better quality product. Not only can the sensor be used in a broad range of products, the design is also flexible and can be adapted as appropriate. “The modular principle of our platforms enables us to respond to manufacturers specific requirements," explained Johannes Mattes. Customers can select which features they want to include or omit, such as smartphone pairing, door handle recess illumination, or headlight activation to help guide drivers to their cars at night.


    Marquardt GmbH
    Schloss-Straße 16
    78604 Rietheim-Weilheim

    Phone +49 74 24 / 99-0
    Fax +49 74 24 / 99-23 99