Touch-on-Metal: HMI for robust, safe operation

Diehl Controls

In modern equipment, the trend is increasingly toward metal panels and the desire to seamlessly integrate the HMI (Human Machine Interface) into the metal panel. Here, Diehl Controls offers robust, safe and hygienically clean operation with a new generation of touch-on-metal controls.

Beautiful, clean and safe - the stainless steel screen as interface
Brushed, matte or shiny - metal panels made of stainless steel or aluminum are not only visually appealing, but also easy to clean and durable. In order to be able to use the surfaces for washing machines, dishwashers, vending machines or sanitary equipment as a man-machine interface, control systems such as those developed, produced and sold by Diehl Controls are suitable. The technology company from Wangen in the Allgäu is a global leader in this field and has many of the major appliance manufacturers on its customer list. In addition, as the name Touch-on-Metal suggests, this technology is used to control electronic devices, machines or automats by applying pressure to the metal surface - without having to drill holes or to punch through the metal.

Controller detects signal starting from one Newton
The latest development from Diehl Controls is an innovative control system integrated directly behind the metal panel. The system used is not only more cost-effective, but also responds more sensitively to signals compared to a piezoelectric solution. While piezoelectric technologies require a short and clear impulse, the new control system works even with different operation, regardless of whether the user presses quickly, slowly, briefly or extensively.

The core of the Diehl Controls' solution is a sensor responding to minute changes on the operator interface. The processing electronics can be activated and a corresponding signal triggered already starting from a pressure force of just one Newton. Thanks to its development expertise in the field of embedded systems, Diehl Controls can adapt each control system to individual requirements on both the hardware and software sides.

System resists high pressure cleaner and steel wool
Since touch-on-metal controls require a defined pressure force, they have a decisive advantage over touch screen applications: Unintentional touches do not lead to malfunctions. This gives users a familiar user experience (UX) and prevents unintentional device operation. The HMI system remains operational even when exposed to temperatures of up to 85 degrees Celsius. Since it is also hermetically shielded under the surface, it is even suitable for underwater applications. When the metal surface is cleaned, the controller withstands the use of hot water, high-pressure cleaners, harsh detergents or steel wool.

Diehl Controls provides its customers with comprehensive support
Especially due to the Corona pandemic, the demand for hygienic and resistant HMI solutions has increased in commercial kitchens, sanitary companies or care facilities. In addition, touch-on-metal controls in the appliance sector are suitable for refrigerators, washing machines, stoves or HVAC (Heating, Ventilation and Air Conditioning) systems and can be used for industrial applications and vending machines.

Diehl Controls not only manufactures controls with high robustness, easy cleaning and long service life but also supports its customers in its development, design, production and service. Various printing processes, such as pad printing, hot stamping, plasma treatment or corona treatment, as well as robot-assisted and fully automatic printing of the metal panels, allow individual customer requirements to be realized in terms of appearance and design.

"Our new touch-on-metal control system is a reliable HMI solution that can be implemented at economically attractive conditions", says Carsten Wolff, President of the Diehl Controls Division Board. "In addition, many customers involve us in product development at an early stage in order to obtain a robust and safe technology for their electronic devices, also with a view to manufacturing, assembly and maintenance."