Frequency Selective Properties of Metal Mesh Optically Transparent Touch Sensor Panels

We design and characterize several optically transparent capacitive touch sensor panels, using a coarse metal-mesh as their trace material. These sensors form periodic patterns on a glass substrate and hence, they can also be considered as finite periodic structures with interesting electromagnetic properties, such as spatial filtering and frequency selectivity. These properties have been largely ignored, despite the fact that they offer many opportunities to integrate multiple functions into touch sensors. The present paper considers three popular touch sensor panel topologies as frequency selective surfaces and absorbers. Without any modification of the geometry, these panels present several pass-bands and stop-bands that can be further tuned to target frequency bands of interest.