A tissue ablation system including numerous components and methods is described herein for encircling target tissue and generating tissue ablation volumes in various biological tissues. The biological tissue includes tissue of a variety of organs of the human body including the liver, spleen, kidney, lung, breast and other organs, but is not so limited. The tissue ablation device comprises an energy source and at least one trocar coupled to the energy source, the trocar having a body, a proximal end, and a distal end. The trocar carries an electrode array that comprises a plurality of electrodes, each electrode of the plurality of electrodes is configured to extend from the trocar when moved from a retracted state to a deployed state, and to have at least one radius of curvature in the deployed state so that the electrode array forms a series of shaped electrodes in the deployed state.
