I am currently working on solid-liquid based contact electrification for triboelectric energy harvesting. While doing a work based on this concept, I have found a problem while measuring power. Since I am working with single electrode mode TENG, I found that when I am trying to measure open circuit voltage against several resistances (where both the TENG device and the resistors should be in parallel connection ), I cannot find any output signal in the multi-meter display. I think I am making mistake to make single electrode based circuit. Can anyone please enlighten me by addressing my concern with any reference or diagram?

Please notice two probes of multi-meter should be attached to this circuit for output visualization in the display.

Thanks in advance