There is provided a monolithically integrated multimodal sensor device for intracranial neuromonitoring, the sensor device including: a single substrate; a temperature sensor formed on a first portion of the single substrate for detecting temperature; a pressure sensor formed on a second portion of the single substrate for detecting intracranial pressure; and an oxygen sensor formed on a third portion of the single substrate for detecting oxygen concentration. In particular, sensing portions of the temperature sensor, the oxygen sensor and the pressure sensor, respectively, are formed at different layers of the sensor device. There is also provided an integrated multimodal sensor system incorporating the sensor device and the associated methods of fabrication.