Navigating biomedical instruments inside the brain remains challenging and high-risk. The delicate nature of the tissues involved requires the development of cutting-edge robotic technologies to enhance precision and safety. In response to these demands, this paper presents a novel ribbon-shaped, tendon-driven continuum microrobot designed explicitly to navigate through brain tissues. The microrobot has a cross-sectional area of 1 mm2, and its design is readily compatible with conventional microfabrication techniques for further miniaturization. The flat geometry aims to provide superior maneuverability and opens up new challenges for modeling and control. We detail the design methodology and fabrication, followed by in vitro characterization and testing within brain tissue phantoms.