A modified dielectric elastomer strain sensor was developed, in order to enhance the accuracy of the measurement of extremely small strains below 1 %. The new sensor consists of two components, which are connected in series along the sensor length. The shorter component is a stretchable dielectric elastomer strain sensor strip, whereas the longer component exhibits a non-stretchable polymer film. When the whole sensor is stretched, the strain occurs only in the stretchable shorter component. Such sensors with enhanced sensitivity were manufactured and investigated with a self-constructed electro-mechanical testing machine. The results of the measurements of capacitance, electrode resistance and stretch force vs. strain were compared with those of corresponding conventional dielectric elastomer strain sensors. Furthermore, the dependence of the capacitance on the strain was calculated with finite element method (FEM) simulations for both sensor types. The sensor design, the results of the experimental characterization and the comparison with the simulation are described in the paper.
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