A thin-film microelectrode array tailored for long-term, minimally invasive cortical recording or stimulation and method are provided. The microelectrode array includes a flexible element that is movable between a first contracted configuration and a second expanded configuration. An array of contacts is provided on the flexible element. The contacts are engagable with a cortical surface with the flexible element in the expanded configuration. A link operatively connects the array of contacts to a control module. The link is capable of transmitting at least one of cortical recordings and cortical stimulation signals thereon.