In one of the DNA-sequencing experiments based on change in pH difference due to release of proton per nuceotide added to DNA. There was considerable pH change in pH due to various factors out of which one was due to the pH-sensor position inside the well; sensor kept stable vs sensor moving in the well in circular motion gives different result. So I invented pH-rocker (the name was given by me)to move sensor in the well in stable circular motion.

http://openwetware.org/wiki/User:Pranav_Rathi/Notebook/OT/2012/05/21/pH-rocker_for_DNA-sequencing_experiments