Untersuchung eines Messsystems zur ortsaufgelösten Dehnungsmessung in zweidimensionalen resistiven Sensorarrays

Soft robotics and wearable electronics are driving the development of highly stretchable, flexible strain sensors. Modern robot systems are increasingly being equipped with additional sensors and extended functionalities in order to achieve human-like perception and interaction capabilities. Tactile perception - the ability to recognize touch and mechanical influences - plays a central role in this, modelled on human skin.

Flexible, two-dimensional strain sensors represent a promising solution for this purpose. They enable the detection of both large-area and locally limited strains and are particularly suitable for the precise detection of complex movement sequences and contact forces. However, suitable measurement and evaluation circuits are required for reliable evaluation of the sensor data.

As part of this work, an existing measuring circuit from the Institute for Measurement Technology at JKU Linz is examined in detail and analyzed with regard to its suitability for stretchable resistance sensors. First, the electrical properties of a single measurement channel are characterized theoretically and metrologically before its behavior in a matrix arrangement is examined, taking into account interactions between grid points.

Analytical calculations, simulations, and experimental measurements are used for validation. Based on the findings, a calibration procedure is developed that improves the accuracy of determining absolute resistance values.

Finally, the procedure is applied to a highly stretchable, two-dimensional strain sensor that is measured under various mechanical loads.

Keywords: strain measurement, sensorarray, two-dimensional, calibration, resistive, spatially resolved, highly stretchable, grid