finished the dc component applied to each selection trace is turned off and the graphene drums of the selection traces disengage the process can then be repeated to read the stated of other graphene drums within other cells using the same process a resonating graphene drum will have a significant variation in capacitance over its range of travel that will also create a unique current response at the resonant frequency that can be used to sense the state of a graphene drum even if tunneling current does not occur another method to read the memory state of all the graphene drums within a cell simultaneously is to apply a voltage signal that contains a superposition of all of the resonant frequencies of the graphene drums the resulting current signal can be then be parsed for individual drum responses using a set of bandpass filters or any other suitable method of time domain or frequency domain signal processing either with analog or digital electronics to change the state of graphene drums within a give cell a relatively high voltage pulse of the same polarity is applied to a given column and row trace resulting in an electrostatic repulsion that frees any graphene drum that was adhered to the column trace at this point an ac signal can be applied to the row and column traces via the selection traces that has a frequency that matches the mechanical frequency of a given graphene drum forcing the graphene drum to resonate until it contacts and adheres to the column trace a different ac frequency can be used to make a different graphene drum within a cell adhere to the column trace fig2 depicts a detailed view.