A bio-based, sweat-resistant and markedly sensitive iontronic skin for advancing central sleep apnea monitoring

Central Sleep Apnea (CSA) is characterized by respiratory pauses during sleep, posing risks like cardiovascular diseases, stroke and sudden death. The challenges in managing it arise from the current monitoring tools, which are often complicated and inaccurate. Furthermore, respiratory pauses leading to decreased blood oxygen can induce profuse sweating, further affecting accuracy. Herein, we have synthesized a bio-based, biocompatible and sweat-resistant polyurethane. By utilizing it as the matrix, we incorporated [BMIM]+[PF6]− to fabricate a markedly sensitive dielectric material, termed i-DFPU. The fluorine groups in i-DFPU contributed to a trap-release effect for migratable ions, while the alkyl side chains provided smooth ion migration channels, endowing i-DFPU with exceptional sensitivity. In combination with a stress concentration layer and serpentine-shaped electrodes, the resultant iontronic skin exhibited a remarkable sensitivity up to 132.2 kPa−1, operational stability and portability. Consequently, it could accurately monitor various respiratory states in CSA, potentially preventing complications such as sudden death.