A highly sensitive, flexible capacitive pressure sensor based on strontium alginate with crater microstructure.

Electronic skin plays an important role in the age of artificial intelligence. Capacitive pressure sensors, capable of sensing pressure changes through contact, still need to improve their basic performance and comfort of use. In this paper, a flexible strontium alginate film with finely folded crater microstructure prepared by spraying method is introduced as a dielectric layer, together with PDMS film and conductive cloth as a capacitive sensor. The internal and external displacement, potential, and elastic volume ratio of the sensor were simulated using finite element analysis. The sensor has good sensitivity (R2 up to 0.99), very low response and relaxation time (≤ 50 ms), and good cyclic stability. The sensor was also used for performing several simple applications tests. • A transparent and ultrathin flexible film with crater microstructure and uniform fine pleated structure prepared by spraying method. • The dielectric constant of the SCA film reached 15.3, which was 1.18 times higher than that of the SA film and 4.5 times higher than that of the PDMS film. • The relative dielectric constant of the dielectric layer increases due to ion displacement polarization generated at the surface of the SCA film. • The capacitive pressure sensor presents high sensitivity, very short response and relaxation times, and good cycling stability. [ABSTRACT FROM AUTHOR]