A micro-actuator for a head gimbal assembly includes a metal frame including a bottom support adapted to be connected to a suspension, a top support adapted to support a slider, and a pair of side arms that interconnect the bottom and top supports. The side arms extend vertically from respective sides of the bottom and top supports. A PZT element is mounted to each of the side arms. Each PZT element includes two PZT portions supported by a PI substrate base. The PI substrate base includes one or more bridges that physically and electrically couple the two PZT portions. The bridges are bendable so that the two PZT portions sandwich the respective side arm when mounted thereto.