The invention relates to a capacitive sensor system, in particular for detecting the approach of objects and in particular also for gesture recognition. The problem of the present invention is to provide a capacitively operating sensor system, which can be implemented with low component complexity and thus low costs and space requirements and is also characterized by low power consumption, so as to operate with batteries having a low charge capacity and/or a long operating time. Said problem is solved according to the invention by a circuit configuration for generating an output signal correlating with an approximation process based on changes in the dielectric properties of the surroundings of a sensor electrode, having a sensor electrode which is adjacent to an observation area in at least some sections, a microcontroller circuit (C) for output of an alternating voltage, a voltage divider circuit for achieving an adjustment of the level of the alternating voltage output by the microcontroller (C), and a field effect transistor (FET) in the function of an impedance converter, wherein the field effect transistor is incorporated into the circuit configuration in such a way that the voltage output by the voltage divider circuit is present at the gate input thereof and at the same time at the sensor electrode (ES).

The present invention provides a sensor apparatus comprising a dielectric elastomer device, a power source, a sensor, and a processor. The dielectric elastomer device comprises a layer of dielectric material and a pair of conductive electrodes on opposing sides of the dielectric layer. The power source is coupled with the electrodes to apply a stimulus signal between the electrodes, the stimulus signal comprising two or more stimulus components of different frequencies. A sensor coupled with the electrodes obtains a sensing signal indicative of a frequency response of the dielectric elastomer device. The processor is coupled with the sensor to receive the sensing signal, and configured to detect an external coupling with the dielectric elastomer device based at least in part upon the frequency response of the dielectric elastomer device. Also provided is a method for sensing an external coupling.

A method for ascertaining manual exertion of a capacitive sensor device, wherein a capacitive sensor element of the capacitive sensor device is exposed to a sinewave-based first electric signal, wherein the capacitive sensor element provides a second electric signal, wherein the second electric signal is input to an in-phase-detector, in order to provide an I-signal, and a quadrature-phase-detector, in order to provide a Q-signal, wherein the I-signal and the Q-signal are processed in order to allow ascertaining the manual exertion. Three predetermined reference impedances are also exposed to the first electric signal, wherein the predetermined reference impedances provide respective second electric reference signals which are input to the in-phase-detector and the quadrature-phase-detector, in order to provide respective reference I-signals and respective reference Q-signals, the reference I-signals and the reference Q-signals are additionally processed.