An implantable device for intrafascicular stimulation and/or sensing of a peripheral nerve, including a blocking element adapted for wrapping a nerve, comprising an access point and an exit point, and an electrode adapted to traverse the blocking element via the access point and the exit point having a distal end, a proximal end and an elongated body in between, the electrode being electrically isolated from the surrounding environment except that for an active site. In another aspect, the invention features a system comprising the implantable device of the invention operably coupled with an external device such an electrostimulator and/or a sensing device for sensing and recording electrical nerve signals.