Ion Track Technology


Reimar Spohr

PostHeaderIcon A small charged channel can be used as pH sensor


With Decreasing Channel Diameter the Influence of Surface Conductivity Increases

Etched surfaces, immersed in salt solutions, carry immobile electric charges. The immobile charges attract mobile counter ions. Close to the surface the conductivity increases. The charge density depends on the acidity/basicity (pH) of the salt solution.

pH Sensor Channel

In small channels the surface conductivity dominates and can be used for pH sensors.


This work profited highly from the work of Dietrich Woermann, University of Cologne, Germany.