Neural electrode made with soft polymers and rapid prototyping techniques

The present invention relates to the field of implantable neural interface devices and, in particular, it refers to a new implantable polymeric neural electrode for extra- or intra-neural applications, as well as to a process for the simple and economically sustainable manufacture thereof. The present invention concerns an implantable neural electrode (100) comprising a flexible main body (10) extending between a first end (10a) and a second end (10b), configured to be at least partially disposed around or inserted within a target nerve, said main body (10) comprises:- a first electrically insulating layer (11); - a second electrically insulating layer (12); and - an electrically conductive pattern (20) interposed between said first and second layers; wherein said pattern (20) comprises a first portion (31), preferably partially outwardly exposed, configured to electrically come into contact with said target nerve, and a second portion (32), preferably outwardly exposed, configured to electrically connect said electrode to an external device; wherein said first layer (11) and second layer (12) comprise at least one polymeric material and said pattern (20) comprises at least one conductive hydrogel or polymer, and wherein said first layer (11), said second layer (12), and said pattern (20) do not contain metallic nanostructures or components. The process for the manufacturing of the implantable neural electrode (100) comprises the following steps: (i) providing a first composition comprising at least one electrically insulating polymeric material or precursors thereof, and a second composition comprising at least one electrically conductive hydrogel or polymer or precursors thereof, wherein said compositions have pseudo-elastic and/or thixotropic properties and do not contain metallic nanostructures or components; (ii) depositing a layer of said first composition on a flat surface of a substrate, so as to form a first electrically insulating layer (11) of said main body (10) comprising said at least one polymeric material; (iii) depositing a layer of said second composition onto the first layer (11) obtained in step (ii) so as to form, onto said first layer, an electrically conductive pattern (20) comprising said at least one conductive hydrogel or polymer; (iv) depositing a layer of said first composition onto the pattern (20) obtained in step (iii) so as to form, onto said pattern, a second electrically insulating layer (12) of said main body (10) comprising said at least one polymeric material, wherein said depositing is carried out in such a way that at least one first portion (31) and at least one second portion (32) of the pattern (20) are left at least partially outwardly exposed; wherein all depositing steps from (ii) to (iv) are carried out by means of an extrusion printing technique.