A method of forming an active matrix, light emitting diode array includes removing, from a base substrate, a layer of inorganic LED material originally grown thereupon; and bonding the removed layer of inorganic LED material to an active matrix, thin film transistor backplane array. The detection circuit is configured to provide a detection signal indicating whether a bit line configured to provide read access to a data bit stored at a memory bit cell has a voltage below a predetermined threshold. 4 m, and calculating the thickness on the basis of a wave form of the reflectance spectrum. The second spindle is disposed coaxially with the first spindle and the hammer is drivingly coupled to the second spindle. A voltage sensor determines a relationship between first voltage at the first capacitive element and second voltage at the second capacitive element to separately control switching of the first and second switching circuitries in accordance with the relationship between the voltages. Examples of protective elements include a collar of material around the core resonator so that perimeter and edge-related environmental and aging phenomena are kept away from the core resonator, a Bragg reflector formed above or below the piezoelectric layer and a cap formed over the piezoelectric layer.