This paper introduces a new technique for electrostatic resonance characterization based on 2nd harmonic distortion terms at the output current. Mathematical analysis of the output current shows that the 2nd harmonic component exhibits higher quality factor (Q) than the 1st harmonic. Besides, output current to feedthrough current ratio is higher in the 2nd harmonic term. Experimental results show that the Q of the resonating system is enhanced by 66% with 2nd harmonic operation. Moreover, the resonance peak has been improved from 0.2 dB to 5dB, showing the effective increase in output current to the feedthrough ratio.