An implantable medical device can include an electrode substrate electrically connected to at least one electrode. The device can have a pseudoporous surface across the electrode substrate and electrode. This surface can result in a real surface area (RSA) greater than the geometric surface area (GSA) of the device. The pseudoporous surface can be a macroporous surface enabling a charge injection capacity greater than 1 mC/cm2 while minimizing rejection of the device by surrounding tissue in chronic implant applications. The electrode can be a thin layer of conductive material, such as platinum or another metal, conformally deposited on the pseudoporous surface of the electrode substrate. A method of making the implantable device can include forming the device having an electrode substrate and at least one electrode electrically coupled to the electrode substrate, and forming a pseudoporous surface on the electrode substrate and electrode.