Compliant and Tough Triboelectric–Piezoresistive Porous Hydrogels Enabled by Interfacial Assembly of Nanocellulose Microgels

Flexible hydrogel materials capable of multimodal sensing are ideal candidates for multidimensional interactive tactile systems. However, conventional approaches based on physically integrated discrete sensors often lead to structural complexity and mechanical compromise. Here, this study proposes an interfacial assembly strategy based on monomer-swollen microgels to prepare a monolithic triboelectric-piezoresistive porous hydrogel with enhanced mechanical flexibility. The tailored porous architecture reduces the hydrogel's modulus from 216.2 kPa to 20.4 kPa, while maintaining excellent mechanical toughness of 329.4 kJ m^-3 and high porosity (73.6%). It also enhances triboelectric output (power density of 0.32 W m^-2) and micropressure sensitivity (increased from 25.9 kPa^-1 to 193.8 kPa^-1 in the 0-200 Pa range). The integrated wearable sensor demonstrates accurate tactile pattern recognition and material discrimination, enabling decoupled and independently quantified dynamic and static tactile stimuli. This study provides a viable strategy for designing simplified, high-performance flexible hydrogel substrates suitable for complex sensing applications.