Wearable Morphology-Adaptive in-Ear Device With Active Cleansing Capability for Multimodal Health Monitoring

Multimodal physiological monitoring using in-ear devices is an excellent solution for nonintrusive and noninvasive health monitoring. However, the small size of the ear canal, variation in its morphology in different individuals, and ear wax introduce challenges such as a non-conformal interface between the sensors and the skin due to the complex ear canal geometry, device fitting issues, biofouling blockage layers, hearing blockage by the device and discomfort. Here, we report a multimodal self-cleansing, in-ear nonintrusive and configurable electronic (SCIENCE) device which adapts to various canal geometries and performs active wax cleaning at the sensor-canal interfaces. Triggered by immersing the sensor in water, the small cylindrical device with a diameter of 2 mm expands once in the ear, and it converts to a spindle shape with a center diameter that can reach 9 mm, thus leading to adaptive contact with the ear canal and forming a stable sensor-canal interface. The proposed in-ear device was also endowed with wax cleaning capability to automatically break the biofouling barrier and decrease the sensor-skin interface impedance by 20%. SCIENCE is integrated with miniaturized circuits and enables simultaneous mobile and wireless recording of electroencephalography (EEG), electrocardiography (ECG), and core body temperature.