Patent ID: 8057508

Claim:
A surgical instrument, comprising: an end effector; a handle portion comprising an articulation control and a locking control circuitry operably configured to produce an unlocking signal; an elongate shaft rotatable relative to the handle portion; an articulation mechanism comprising: a proximal frame portion attached to the elongate shaft, a distal frame portion attached to the end effector and rotatably coupled to the proximal frame portion to form an articulation joint, and an articulation actuator responsive to the articulation control of the handle portion and coupled between the proximal and distal frame portions and operably configured to effect articulation therebetween; and an electrical locking mechanism positioned between the handle and the end effector and movably engageable between the proximal and distal frame portions to lock the end effector at an angle relative to the elongate shaft by locking the articulation joint, wherein the electrical locking mechanism comprises: a locking member attached to the proximal frame portion or the distal frame portion, wherein the locking member is biased to extend toward and engage the other one of the proximal frame portion or the distal frame portion to lock the articulation joint, wherein the locking mechanism further comprises a resilient member resiliently biasing the locking member to extend toward and engage the other one of the proximal frame portion or the distal frame portion to lock the articulation joint, wherein the locking member is located at the articulation joint, and an electroactive polymer actuator coupled with the locking member, wherein the electroactive polymer actuator is operatively configured and positioned to overcome the bias on the locking member and move the locking member when activated by the unlocking signal to unlock the articulation joint.