Patent ID: 8384372

Claim:
A method of determining characteristics within an environment, comprising: providing an at least semi-conductive element; locating a counter electrode a predetermined distance from the element such that the element and the counter electrode are in a non-contacting relationship; locating the at least semi-conductive element and the counter electrode within an environment; inducing an electrostatic force on the element by applying a first electrical signal, composed of an AC waveform and a DC component, between the counter electrode and the element, the AC waveform being applied in a pulsed ring-down mode having an on state and an off state, the element being allowed to freely oscillate in a non-linear field resulting from the DC component of the first electrical signal during the off state of the AC waveform; generating a second electrical signal in response to changes in distance between the counter electrode and element based on movement influenced by the induced electrostatic force and the environment; and examining the waveform of the second electrical signal during the off state of the AC waveform to analyze time dependent variations in frequency, amplitude, or phase of non-linear oscillations and their harmonics within the second electrical signal.