Flexible Sensors with Enhanced Sensitivity and Broadened Detection Range Through Conformal Printing and Space-Confined Design.

Enhancing the sensitivity and extending the linear sensing range of flexible pressure sensors are crucial for their development and incorporation in wearable electronics. Conventional sensors face a trade-off between sensitivity and linear sensing range, which is often limited by the monotonicity of materials and structural design. To address this challenge, a new piezoresistive flexible sensor is developed in this work, drawing inspiration from the intricate microstructure and pressure-sensing capabilities of human skin. This advanced sensor is constructed with a dual-layer resistive sensing design, which includes an external conductive layer comprising of MXene/Ag composite and an internal carbon nanomaterial conductive network. The design incorporated bionic micro-spines and multilayer porous microstructures with microcapsules to optimize the overall performance. This scalable and economical approach yielded a sensor that surpassed human tactile resolution, and the sensor can adeptly monitor comprehensive human motions and respiratory rhythms and recognize spoken language. In addition, it exhibited reliable photothermal sterilization performance, making it suitable for long-term health diagnostics and treatment. The proposed sensor demonstrated immense potential for applications in physical health monitoring, motion detection, electronic skin, and human-computer interactions.