New AFSEM publication: Development of a transparent touch sensor on reconstituted veneers
A recently published study by our client Wood K Plus Transparent Touch Sensors on Wood: Sustainable Development With Aesthetic Integrity presented the development of a transparent touch sensor on reconstituted veneers. This innovative technology could pave the way for the seamless integration of advanced electronics into wood surfaces while preserving their functionality.
Structure and function of the sensor
The touch sensor was applied to the veneer using a screen printing process with silver nanowire ink. A protective coating on the sensor prevents reactions to ambient humidity, which significantly increases the reliability and service life of the sensor.
Topography and distribution of the silver nanowires
Both scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the surface structure and the distribution of the silver nanowires on the coated veneer. The SEM images clearly showed the layer of silver nanowires and the transition from the veneer substrate to the printed sensor structures. Interestingly, this transition is not abrupt, but shows a gradual increase in nanowire density at the edges of the sensor line.
The applied layer of silver nanowires consists of a very loose network, as the amount of ink applied was deliberately kept low. This low network density was also confirmed by the AFM measurements.
AFM amplitude images of the veneer substrate, the transition area between substrate and sensor and the structure of the silver nanowire network in the printed sensor line again showed a low network density. The topography images of the AFM measurements made it clear that the nanowires adapt well to the structure of the veneer substrate. Despite the low density of the deposited silver nanowire layer, the sensor response and performance were extremely satisfactory.
Special features of the AFSEM system
The AFSEM system was used for the AFM measurements and delivered outstanding results. The AFSEM, an AFM designed for integration into an SEM, combines the advantages of atomic force microscopy with those of scanning electron microscopy. This system allows precise analysis of the surface structure and distribution of materials on a nanometric scale, while simultaneously capturing high-resolution images of the overall structure. The use of the AFSEM system was instrumental in gaining detailed insights into the behavior of the silver nanowires on the veneer and confirming the efficiency of the sensor.
More about AFSEM - correlative AFM and SEM