A simple method for constructing shielded, low-capacitance glass microelectrodes

A new simple method is presented to produce shielded low-capacitance microelectrodes. A metal-shield is vapour-deposited on the inner surface of a glass pipette which is slid over the microelectrode proper and insulated at the tip by dipping in polystyrene. The unshielded protruding tip can be as small as 10 micrometers. A special advantage is the low capacitance between electrode and shield of approximately 0.16 microF/cm shield length.