Flexible Biosensor Based on Electrospun H3PO4@PVP Nanofibers with Improved Detection Range for Wearable Pressure Sensing

Abstract

Flexible pressure sensors are gaining increasing attention in areas such as human movement monitoring and human–computer interaction. However, maintaining good sensitivity over a wide detection range is still very challenging. This paper introduces a flexible capacitive pressure sensor distinguished by its high performance and broad detection range. The H₃PO₄@PVP composite nanofibers membrane is created using the electrospun technique, which resulted in an extensive detection range (0–800 kPa) and maintains a high sensitivity over this range (0.506 kPa^–1@ 0–100 kPa, 0.230 kPa^–1@ 100–600 kPa, and 0.041 kPa^–1@ 600–800 kPa). In addition, the proposed biosensor exhibits a short response time of ∼44 ms and remains stable after undergoing 3500 load-unload cycles. Consequently, the biosensor captures physiological signals from various locations on the human body, detects body movements, and monitors interactions between the human body and the external environment. Furthermore, with the assistance of the developed Microcontroller Unit (MCU) detection and display system, the proposed biosensor can accurately perceive external ambient pressure, making it a true tactile biosensor that demonstrates exceptional sensitivity to both ultralow and high pressures generated by human activities.