Flexible Multi-level Hierarchical Architectural Integrated Pressure-Temperature Sensor with High Sensitivity, Wide Working Range, and Independent Stimulus Discriminability

Wearable multi-functional 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 multi-parameters independently decoupled is still a critical challenge. Here, a multi-level 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 multi-level 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 ultra-low 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 ultra-low pressure detection limit of 3 Pa, and a high temperature sensitivity of -1.85%/°C over 25 to 60 °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.