A surgical mechanical arm comprising: an electrosurgical tool comprising: a first tool portion comprising a first surface; a second tool portion comprising a second surface, where said tool portions are mechanically coupled and configured to move relative to each other to change a separation between said first and second surfaces; a first elongated element electrically coupled to at least a part of said first tool portion which is electrically isolated from said second tool portion; and a second elongated element electrically coupled to at least a part of said first tool portion and mechanically coupled to and configured to actuate one or both of said tool portions to change said separation between said first and second surfaces.