Electrostatic Jet Engineering of Flexible Composite Pressure Sensors for Physical Applications

Design and fabrication of highly sensitive and flexible sensors is an area of intense interest and research but is limited with respect to the detection range and application (e.g., deployment in both terrestrial and aquatic environments). Here, we present flexible pressure sensors (FPSs) comprising graphene–PANI-embedded polyethylene oxide and exhibiting ultralow detection limits. These sensors were prepared using a modified electrohydrodynamic (EHD) jetting method and enabled wearable monitoring of physiological parameters and selective aquatic life activity. Sensor thickness, resistance, and sensitivity were modulated through jetted layers. Through EHD jetting, the minimum detected static pressure was seen to be 12 Pa. The strain resistance test displayed a gauge factor of 5.5 under a bending strain of 12.5–50%. FPS engineering was performed using a green, sustainable, and cost-effective approach and demonstrated high sensitivity, ultralow detection limits, rapid response, and excellent mechanical durability. Detection of minute signals during physical activity (e.g., finger movements, facial expression, cough, hand gestures, acoustic vibrations, and real-time pulse waves of near-body states) was shown. Furthermore, real-time detection of underwater activity elucidates the potential in emerging healthcare, environmental, and bio-related monitoring.