Figure 2
From: Tribotronic control of an ionic boundary layer in operando extends the limits of lubrication
Schematic of modified EHD2 with a 2-electrode setup. The working electrode (WE) of the potentiostat (a) is connected to the ball drive shaft (b) through a slip ring body (c) and slip-ring brush (d). The drive shaft is further electrically connected to the ball (e) through a coiled wire (f). The drive shaft is electrically insulated form the rest of the equipment by the use of ceramic bearings (not shown). The counter electrodes (CE) for the setup are composed of two stainless steel blocks (g) on either side of the ball. The inner face of the blocks has a spherical face allowing a gap of approximately 0.5 mm between each CE and the ball surface (inset). These block are held in place by a frame (h) which is integrated into the ball carriage (i), which is composed of a 3-bearing geometry (ceramic bearings for electrical insulation) on which the ball rests. A strip of PTFE (not shown) electrically insulates the blocks from the frame. The blocks are connected to the potentiostat CE terminal using a set of wires (j). The ball carriage translates vertically to obtain the required contact load between the ball and the glass disc (k). (Solidworks 2019, Dassault Systèmes; available at https://www.solidworks.com/).
