Flexible Multilevel Hierarchical Architectural Integrated Pressure-Temperature Sensor With High Sensitivity, Wide Working Range, and Independent Stimulus Discriminability

Wearable multifunctional sensors have attracted favorable attention due to their promising applications in artificial limbs, health monitoring, and human-machine interfaces. However, developing the intrinsic integrating sensors embowed multiparameters independently decoupled is still a critical challenge. Here, a multilevel hierarchical architectural integrated dual-functional sensor with shared electrodes is proposed to decouple pressure and temperature signals independently. The capacitive pressure-sensitive layer is constructed by the designed unique dot-knot micro-structures to obtain the multilevel hierarchical architecture with the thermoplastic polyurethane@polyaniline (TPU@PANI) membrane. The designed micro-structures effectively realize the pressure sensing in stage to obtain an ultra-wide measurement range and an ultralow pressure detection. Meanwhile, the hierarchical micro-structure buffers the pressure acting on the temperature-sensitive layer to solve the signal crosstalk. The resistive temperature-sensitive layer is formed with a serpentine-shaped nickel oxide (NiO) film based on the negative temperature coefficient (NTC) effect by microelectronic printing. The proposed sensor processes an ultra-wide pressure range of 23 MPa, high linearity values of 0.998 and 0.991 in ranges of 0–580 kPa and 10–23 MPa, an ultralow pressure detection limit of 3 Pa, and a high temperature sensitivity of −1.85%/°C over $25~^{\circ }$ C– $60~^{\circ }$ C. Demonstrations of the presented flexible integrated sensor to monitor vocalization, motion, breathing, and object grabbing/releasing in various application scenarios involving coupled pressure/temperature stimuli exhibited its excellent potential capabilities in wearable electronics.