Production of PyzoFlex®-Sensors

Production on an industrial scale is carried using a low-cost screen printing process. The finalized, printed sensors are electrically activated with a hysteresis poling and are, thereafter, multi-functional.

The substrate of the printed sensors is a transparent plastic substrate made of PET, but other materials such as glass or coated paper can also be used. In a first step, horizontally mounted ground electrodes are printed. Subsequently, the entire substrate is coated with functional or activated material. In the last step, a layer is applied with vertically mounted covering electrodes. The ground and upper electrodes are superimposed directly over one another and form a plate capacitor. Charge displacements in the intermediate ferroelectric layer generate an electric voltage between the two electrodes.

Porous Printing

Screen printed PyzoFlex® foil with the half automatic screen printing machine THIEME Lab 1000 with a double camera alignment sytem allowing high-precision printing of funcional layers

The sensor layer made of ferroelectric copolymer P (VDF-TrFE) is nearly transparent. If a more transparent sensor film is needed, the upper electrode can also be printed with PEDOT: PSS, resulting in about 85% transparency. Optimization for the detection of changes in temperature or IR radiation in the sensor film can be achieved by printing the uppermost electrode layer with a more highly absorbent carbon ink. A great advantage of this manufacturing method is that the printing process has few expensive requirements (cleanroom environment, vacuum vapor deposition, high temperatures) and, thus, enables a low-cost industrial production.

Screen printed, ferroelectric PVDF:TrFE sensor matrix used for novel human-machine interfaces, which enables new, pressure-based, intuitive interactions between humans and machines (computer).

Hysteresis Polung

The piezo- and pyroelectric properties of the sensor material are activated by electrical poling. During the printing process, randomly oriented dipoles in the material align themselves vertically with respect to the sensor electrodes.