Advanced interactive surfaces by TNO at Holst Centre: consoles and control panels re-invented

 

TNO at Holst Centre (Eindhoven, The Netherlands) supports companies in the development of interactive surface technologies using structural electronics based on printed electronics that can be formed into any 3D shape, making rigid printed circuit boards a thing of the past. Printed circuit boards demand volume, cannot be adjusted in shape and are less cost-effective. With the approach TNO at Holst Centre has developed for structural electronics, both graphic and electronic parts are printed directly onto the backside of a substrate, creating a closed and smooth surface that contains all electronic functionalities. Touch buttons and icons can be located anywhere, on any surface and in any size. Technology design is therefore no longer restricted and pre-defined.

Margreet de Kok, programme manager Structural Electronics at TNO at Holst Centre: "We are used to buttons and switches on our home appliances and in our car interiors that have to be pressed in order to activate them. Now imagine having complete design freedom for these buttons, and turning them into interactive, dynamic icons that do not have a fixed position, but can be integrated anywhere on a device or console. This would allow a control panel to be programmed after production and reprogrammed on demand. Application possibilities would be endless. You may have your audio controls in your car door, if that is where you want them to be. You could have a non-flat, free-form display in an elevator with a variety of options: showing company videos or displaying promotional material. Anything is possible."

TNO at Holst Centre has developed a technology for printed electronics based on a single substrate approach. By printing both graphic and electronic parts directly on the backside of a substrate, all printed electronics are contained in one piece of foil. As a result, these applications are much thinner and the production process is much less time-consuming, reducing both costs and waste.

The centre has developed a demonstrator that combines proximity sensing with direct touch detection by using printed electronics and discrete components such as LEDs, time-of-flight sensors and OLED displays, creating freely programmable back-lit icons. It was the first time that anyone has been able to give a display a 3D shape by thermoforming the total stack.

Another prototype was realised by integrating printed electronics in the control panel of a coffee machine, combining capacitive touch and sliders with surface-integrated LEDs, resulting in homogeneously lit icons. The total thickness of the device is only 3mm.

Caption: Printed electronics in a coffee machine – capacitive touch and sliders with integrated LEDs (photo: Holst Centre)