Wide linear range and highly sensitive flexible pressure sensor based on multistage sensing process for health monitoring and human-machine interfaces

The multi-dimensional carbon materials are incorporated into the polydimethylsiloxane matrix to construct a flexible pressure-sensitive film with micro-patterns array on the surface (P-HCF). The P-HCF sensor demonstrated high sensitivity of 26.6 kPa −1 in a wide linear sensing range (20 Pa − 600 kPa) for monitoring physiological signals. Additionally, the sensor is integrated into the wearable device for human–machine interfaces. • Micro-nano hybrid-structured conductive film with arched micro pattern array. • The flexible pressure sensors with multistage sensing. • The sensors demonstrate outstanding linear sensitivity and wide sensing range. • The pressure sensors sensitive to health monitoring and human-machine interfaces. Flexible pressure sensors have promising applications in wearable electronic devices. However, fabricating flexible pressure sensors with wide linear range and high sensitivity remain a great challenge. Herein, a micro-nano hybrid conductive elastomer film based on carbon materials with arched micro-patterns array on surface (P-HCF) is developed to show expected sensing properties through a sustainable route. The 1D carbon fibers (CFs) and 0D carbon nanoparticles (CNPs) were incorporated into polydimethylsiloxane (PDMS) matrix to construct a 3D conductive network consisting of physical contact and tunneling effect among carbon materials to improve the sensing range and sensitivity. The arched micro-patterns of the P-HCF, which is designed mimicking the human fingerprints, influences the pressure distribution inside the material, giving rise to a linear sensitivity over the whole sensing range. Finite element analysis (FEA) method is investigated to simulate and analyze the compression process. The P-HCF sensor exhibits both a high sensitivity of 26.6 kPa −1 and an exceptionally wide linear range of 20 Pa − 600 kPa. The devices were demonstrated in monitoring artery pulses, assisting in diagnosing Parkinson's disease, and analyzing gait for healthcare. Furthermore, the sensors are integrated into complex devices to realize pressure distribution detection, controlling manipulator, and operating PC games. The attainment of excellent pressure sensing performance of the P-HCF, potentially initiates vast applications in health monitoring and human-machine interfaces.