Sequentially Stacked Graphene/Carbon Black Langmuir–Blodgett Heterostructures for Pressure-Crosstalk-Suppressed Strain Sensing
Shaohao Wang, Junhao Shen, Leping Sun, Jiajie Cui, Zewen Gan, Xu Ran, Xiaomei Li, Chunhua Cai, Xing Wu, Hengchang BiAbstract
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.