The present disclosure relates to exhaust gas emissions in motor vehicles. The teachings thereof may be embodied in soot sensors. For example, a soot sensor may include: a first electrode; a second electrode; an insulation body between the first electrode and the second electrode configured to allow soot particles to pass with a gas flow into a space defined between the first electrode and the second electrode; a meter evaluating a current between the first electrode and the second electrode resulting from an electrical voltage applied between the first electrode and the second electrode; and elements concentrating the electric field strength formed on at least one of a surface of the first electrode or a surface of the second electrode.
1. A soot sensor comprising:
a first electrode;
a second electrode defining an internal cavity having a longitudinal extent and radially surrounded by material of the second electrode;
wherein the first electrode is disposed at least partially within the internal cavity of the second electrode;
an insulation body electrically separating the first electrode and the second electrode from one another, the insulation body in physical contact with both the first electrode and the second electrode, projecting into the internal cavity, and configured to allow soot particles to pass with a gas flow into the internal cavity between the first electrode and the second electrode;
a meter evaluating a current between the first electrode and the second electrode resulting from an electrical voltage applied between the first electrode and the second electrode; and
elements concentrating the electric field strength formed on at least one of a surface of the first electrode or a surface of the second electrode.
2. The soot sensor as claimed in claim 1 , wherein the first electrode comprises a rod shape.
3. The soot sensor as claimed in claim 1 , wherein the second electrode comprises a cylindrical shape.
4. The soot sensor as claimed in claim 2 , wherein the second electrode comprises a cylindrical shape arranged concentrically around the rod-shaped first electrode.
5. The soot sensor as claimed in claim 1 , wherein the elements comprise spike-like tips.
6. The soot sensor as claimed in claim 1 , wherein the elements comprise triangular tips.
7. The soot sensor as claimed in claim 1 , wherein the elements comprise nanostructures on the surface of the first electrode or the surface of the second electrode.