The present invention provides an electrode array (1) for a medical implant device, comprising a substrate (2) supporting a plurality of electrodes (3), the substrate (2) comprising at least two layers of material including a first layer (4) and a second layer (5), wherein the first layer of material (4) and the second layer of material (5) have different coefficients of thermal expansion. The plurality of electrodes (3) may be supported on the first layer of material (4), and are preferably incorporated in and/or project from the second layer of material (5). The second layer of material (5) may itself have a layered structure comprising multiple material layers (51, 52, 53), with the plurality of electrodes (3) incorporated within the said multiple material layers (51, 52, 53). The first layer of material (4) preferably has a higher coefficient of thermal expansion than the second layer of material (5). The invention furthermore provides a medical implant device (10) including an electrode array (1) according to the invention, and a method of manufacturing such an electrode array (1).
