Auricular bioelectronic devices for health, medicine, and human-computer interfaces

Recent advances in manufacturing of flexible and conformable microelectronics have opened opportunities for health monitoring and disease treatment. Other material engineering advances, such as the development of conductive, skin-like hydrogels, liquid metals, electric textiles, and piezoelectric films provide safe and comfortable means of interfacing with the human body. Together, these advances have enabled the design and engineering of bioelectronic devices with integrated multimodal sensing and stimulation capabilities to be worn nearly anywhere on the body. Of particular interest here, the external ear (auricle) offers a unique opportunity to design scalable bioelectronic devices with a high degree of usability and familiarity given the broad use of headphones. This review article discusses recent design and engineering advances in the development of auricular bioelectronic devices capable of physiological and biochemical sensing, cognitive monitoring, targeted neuromodulation, and control for human-computer interactions. Stemming from this scalable foundation, there will be increased growth and competition in research and engineering to advance auricular bioelectronics. This activity will lead to increased adoption of these smart headphone-style devices by patients and consumers for tracking health, treating medical conditions, and enhancing human-computer interactions.