Indirect measurement and recognition of human finger motion via flexible piezoelectric POSS-doped poly(L-lactic acid) sensor

Advancements in wearable technology and human–computer interaction have led to the development of flexible sensors capable of recognizing subtle human motions, such as finger movements. Among various sensor types, piezoelectric materials exhibit unique properties that respond to mechanical stress with an electrical output, making them suitable for motion detection applications. This work explores an innovative approach using a flexible piezoelectric sensor fabricated from polyhedral oligomeric silsesquioxanes (POSS)-doped poly(L-lactic acid) (PLLA) to measure and recognize human finger motions indirectly. The sensor developed based on this film, encapsulated with an innovative photocurable elastomer film, exhibits high sensitivity (65.61 mV∙kPa −1 ), rapid response (0.033 s), and stable output, enabling the precise detection of weak physiological signals, such as radial artery pulses, compared to conventional sensors. Additionally, the sensor, combined with fast continuous wavelet transformation and a Swin Transformer classifier, achieves 97.96% accuracy in recognizing nine categories of finger motions. The combination of flexibility, biocompatibility and enhanced piezoelectric properties positions this sensor as a promising tool for developing advanced human–computer interfaces.