Triboelectricity is an electrical charge created by relative movement between two non-conducting solid surfaces in contact. The relationship with Tribology should be clear! The tribolelectric effect depends on the material properties of the two surfaces and is usually strongest when they are electrical insulators and are separated by an insulating medium.
Normally, triboelectricity is a problem. People are annoyed by the electric shocks that are generated by the movement of their footwear on certain floor coverings, or by certain clothing. Sensitive electronic devices can be destroyed by the momentarily high discharge currents that can be developed. The most dramatic form of triboelectricity is probably lightning, which is the rapid discharge of electrical energy stored by collisions between ice particles moved around by the air.
This article explains that static electricity can build up within a hydraulic filter. It does not fully explain the process. Assuming that pairs of solid surfaces are required, perhaps the process involves relative movement of adjacent fibres within the weave of the filter element?
This article explains that the static buildup is due to the relative movement of the solid filter element and the fluid. After several years working in hydraulics, where deductive investigation is commonplace, I find that explanation to be a remarkable achievement. It turns out that two solid surfaces are not required after all!
In a future posting I will explain what I have recently learned about the beneficial and very exciting application of triboelectricity. I hope that IET members will be inspired to find out about Tribology as a result.
