We proposed a sensing–transducing coupled strategy by embedding the high piezoresponse Sm-PMN-PT ceramic into a moisture-sensitive PEI via electrospinning to conjugate the humidity perception and signal transduction synchronously and sympatrically.

Moisture detection plays a crucial role in physiological monitoring and wearable electronics. Nevertheless, most of the humidity sensors were restricted by the power supply, hindering their applicability in internet of things and mobile healthcare. Herein, we reported a hierarchical piezoelectric composite film for active humidity detection and wearable biomonitoring. The as-electrospun piezoelectric transducing textile consists of samarium-modified lead magnesium niobate lead titanate piezoceramic fillers and polyvinylidene fluoride matrix, while the spin coated polyimide film serves as the humidity sensitive layer. By tuning the thickness ratio between transducing layer and the humidity sensing layer as well as the porosity of the electrode, an optimal moisture-sensing performance was accomplished with a high response of ∼500% and rapid response/recovery time of 23 s/31 s. Furthermore, a theoretical modeling of active humidity sensing mechanism was established by combining thermodynamic derivation and finite element calculation.

As an important neurotransmitter, the concentration of dopamine (DA) reflects certain physiological conditions and DA-related diseases. Rapid monitoring of DA levels is of great significance in regulating body health. However, regular electrochemical DA sensors suffer from poor sensitivity, low selectivity and interference immunity, as well as a complex preparation process. Herein, we developed an accessible and cost-effective electrochemical sensor with a copper indium selenide (CuInSe₂ or CIS)-modified screen-printed carbon electrode for DA discrimination. This DA sensor was developed using a facile one-step hydrothermal method without high-temperature quenching. Benefitting from the inherent merits of CIS and the conversion of Cu²⁺ and Cu⁺ during the catalytic reaction, the sensor attained both excellent sensitivity (2.511 μA·µM⁻¹·cm⁻¹) and selectivity among multiple substances interfering with DA. This work demonstrates the potential to improve the analytical performance of traditional electrochemical sensors.