Bipolar electrosurgical instrument with replaceable electrodes

A bipolar electrosurgical instrument (10) comprises a first member (13) having a first jaw (19) near a distal end of the instrument, and having a first handle (16) near a proximal end of the instrument; a second member (14) having a second jaw (20) near the distal end and having a second handle (17) near the proximal end and a pivot joint (15) connecting the first and second members to allow for arcuate motion of the first and second jaws toward each other. A first mechanical interface is provided on the first jaw, and a second mechanical interface on the second jaw; first and second electrodes (11,12) removably mounted in the first and second mechanical interfaces, respectively, wherein each of the first and second electrodes has an electrically conductive seal surface (24) and an electrically insulative substrate (25), the insulative substrate being overmolded to capture the electrically conductive seal surface. A first ratchet (29) is provided on the first handle, and a second ratchet (30) on the second handle, wherein the first and second ratchets interlock in at least one position (31), and wherein the position holds strain energy in the first and second members to force the first and second electrodes against each other in opposition.