Mutual Inductance-Based Array Sensor for Continuous Monitoring and Mapping of Localized Brain Deformations

The brain undergoes constant dynamic deformations, which are intricately linked to its intrinsic properties and pathological states. However, continuous monitoring of these deformations presents significant challenges due to the limited temporal and spatial resolutions of conventional imaging techniques. Here, it is developed an implantable deformation array sensor capable of real-time, continuous monitoring and mapping of brain deformations. The sensor features microcoil arrays embedded in ultrathin films and operates based on the principle of mutual inductance, achieving exceptional temporal resolution (<100 µs) and distance resolution (<5 µm). It is implanted the sensor between the skull and the cortex and successfully tracked continuous brain deformations across four cortical sites in rat models. These experiments are conducted under scenarios of isoflurane inhalation, mechanical impacts, and intracranial hemorrhage, where such detailed monitoring and mapping has not been achieved previously. The results reveal that brain deformations dynamically vary over time in response to both physiological fluctuations and pathological events, with deformation amplitudes decreasing as the distance from the primary site increases. This innovative approach provides a novel platform for exploring brain dynamics and their associations with neurological disorders and disease progression.