Sequentially Stacked Graphene/Carbon Black Langmuir–Blodgett Heterostructures for Pressure-Crosstalk-Suppressed Strain Sensing

Reliable resistive strain sensors require high tensile sensitivity with minimal interference from normal pressure, which remains a challenge for disordered conductive networks. Here, we report sequentially stacked graphene/carbon black (Gr/CB) Langmuir–Blodgett (LB)-like heterostructures for pressure-crosstalk-suppressed strain sensing. The films are prepared by spray-induced air-water interfacial assembly and cyclic water-assisted transfer, enabling Gr/CB deposition on elastomeric substrates. Gr layers form crack-sensitive pathways for tensile strain transduction, while CB interlayers act as distributed conductive bridges. During stretching, CB refines crack evolution and preserves percolative transport over a broad strain range. Under normal compression, CB-rich interfaces likely create additional conductive contacts, mitigating resistance fluctuations. The optimized 3L Gr/CB sensor operates up to 150% strain, with gauge factors of 15.9, 52.7, and 187.1. It retains tensile sensitivity comparable to the 3L Gr sensor while reducing the compression-induced crosstalk ratio to 3.2%. Integrated into a smart glove, the sensors improve gesture recognition accuracy from 88.0% to 98.9% and enable wireless control of a robotic hand and unmanned aerial vehicle. This work presents an interfacial stacking strategy for pressure-crosstalk-suppressed, flexible strain sensors for wearable human-machine interaction.