Patent ID: 8197655

Claim:
A system for detecting interaction between substances, comprising: a reaction field for allowing said interaction to proceed between said substances, said interaction occurring due to the application of a low frequency voltage resulting in a desired electrodynamic effect; and a voltage application section for applying a voltage to a working electrode arranged facing said reaction field, the working electrode having an insulating film covering the surface of the working electrode; wherein said voltage application section synthesizes two sinusoidal voltages of different frequencies to generate a resultant signal having a low frequency beat, and having a sufficiently high frequency component such that the resultant signal penetrates the insulating film covering the surface of the working electrode, and the beat generated from the two sinusoidal voltages has a resulting beat frequency sufficiently low to cause the desired electrodynamic effect, allowing said interaction to proceed between said substances; and wherein said voltage application section uses an electric circuit, which by half-wave rectification alternately cuts off positive and negative polarities in consecutive half cycles of the beat.