Embodiments herein describe a capillary containing a eutectic conductive liquid (e.g., EGaIn) and an electrolyte (e.g., NaOH) that is integrated into a printed circuit board (PCB). In one embodiment, the capillary is formed in a through-hole in the PCB and has negative and positive electrodes at its respective ends to seal the eutectic conductive liquid and the electrolyte. The capillary further includes one or more electrodes that extend through a side of the portion of the capillary containing the liquids. The wiper electrodes also make electrical contact with respective conductive layers in the PCB. Using a DC voltage between the negative and positive electrodes, the eutectic conductive liquid forms electrical connections between the wiper electrodes, which in turn, forms electrical connections between the conductive layers in the PCB.