Patent attributes
An apparatus comprises an electrically active layer having a first plurality of substantially parallel electrodes and a second plurality of substantially parallel electrodes, wherein the first plurality of electrodes are not parallel to the second plurality of electrodes, such that there exists a matrix of intersection points between the electrodes. A signal generator is configured to generate excitation signals and is connected to the first plurality of electrodes, and a signal detector is configured to detect output signals from the second plurality of electrodes, wherein an output signal from one of the second plurality of electrodes is indicative of the degree of capacitive coupling to one of the first plurality of electrodes on application of an excitation signal thereto. A flexible top layer is sealed to the electrically active layer to define at least one hermetic void between portions of the top layer and portions of the electrically active layer.
