Helical core ear implant electrode

An intracochlear electrode array configured to be implanted within the cochlea of an implanted patient, the electrode array comprising:

• an electrode array core comprising a plurality of thin-film layers of a flexible polymer material, the electrode array core having an apical end and a base end and including:
• i. a first portion towards the apical end having an elongated helical shape with the plurality of thin-film layers configured to form a plurality of helical turns without residual stress, and
• ii. a second portion towards the base end configured to have a straight planar shape;
• a plurality of electrode wires embedded within the array core for carrying electrical stimulation signals;
• at a terminal end of each electrode wire, an electrode stimulation contact exposed through the array core for applying the electrical stimulation signals to adjacent neural tissue;
• and
• an electrode carrier of resilient material encasing the electrode array and having an outer surface with a plurality of contact openings exposing the stimulation contacts;
• wherein the material of the electrode carrier and the helical turns of the first portion of the electrode array core are configured to cooperate to provide flexibility for lateral bending during insertion of the electrode array into the cochlea of the implanted patient;
• and
• wherein he material of the electrode array and the straight planar shape of the second portion of the electrode array core are configured to cooperate to provide rigidity that requires increased lateral bending force for handling by a surgeon implanting the electrode array into the cochlea of the implanted patient.