Rational design of a multi-level tri-MCUT//foam-MCP heterostructure for highly sensitive and compressible physiological signal monitoring

Achieving both high sensitivity and a broad sensing range in flexible piezoresistive sensors via cost-effective methods remains a challenge. We propose a multi-level heterostructure, Tri-MCUT//Foam-MCP, integrating an electrospun MXene/CS/UIO-66-NH2@TPU (MCUT) nanofiber membrane with a compressible MXene@CS@PU (Foam-MCP) foam. The sensor leverages a gradient response: the outer MCUT layers provide high low-pressure sensitivity (41.69 kPa−1), while the inner foam core enables a wide operating range (0-100 kPa) with high gauge factor (GF = 310.1). This rational design effectively resolves the trade-off between sensitivity and measurement range, demonstrating exceptional durability and performance when monitoring both subtle (pulse, blinking) and macroscopic (joint movement) human physiological signals.