The brain is actuated by billions of neurons with trillions of interconnections that regulate human behaviors. Understanding the mechanisms of these systems that induce sensory reactions and respond to disease remains one of the greatest challenges in science, engineering, and medicine. Recent advances in nanomaterials and nanotechnologies have led to the extensive research of electronic devices for brain interfaces to better understand the neural activities of the brain’s complex nervous system. The development of sensor devices for monitoring the physiological signals of the brain related to traumatic injury status has accompanied by the progress of electronic neural probes in parallel. In addition, these neurological and stereotactic surgical revolutions hold immense potential for clinical analysis of pharmacological systems within cerebral tissues. Here, we review the progress of electronic devices interfacing with brain in terms of the materials, fabrication technologies, and device designs. Neurophysiological activity can be measured and modulated by brain probes based on newly developed nanofabrication methodologies. Furthermore, in vivo pathological monitoring of the brain and pharmacological assessment has been developed in miniaturized and wireless form. We also consider the key challenges and prospects for further development, and explore the future directions emerging in the latest research.

Light-mediated therapeutics have attracted considerable attention as a method for the treatment of ophthalmologic diseases, such as age-related macular degeneration, because of their non-invasiveness and the effectiveness to ameliorate the oxidative stress of retinal cells. However, the current phototherapeutic devices are opaque, bulky, and tethered forms, so they are not feasible for use in continuous treatment during the patient’s daily life. Herein, we report wireless, wearable phototherapeutic devices with red light-emitting diodes for continuous treatments. Red light-emitting diodes were formed to be conformal to three-dimensional surfaces of glasses and contact lenses. Furthermore, fabricated light-emitting diodes had either transparency or a miniaturized size so that the user’s view is not obstructed. Also, these devices were operated wirelessly with control of the light intensity. In addition, in-vitro and in-vivo tests using human retinal epithelial cells and a live rabbit demonstrated the effectiveness and reliable operation as phototherapeutic devices.