Ultrabroad Linear Range Composite Graphene Foam Force Sensor Based on Bio-Frog for Human Motion and Soft Robots

Based on the snap response, environmental adaptability, and cycle stability, flexible force sensors have been the Holy Grail in the field of modern intelligent sensing. Meanwhile, force sensors have attracted significant attention owing to their broad applicability in human–machine interface and health detection. However, achieving high sensitivity across a wide linear pressure range remains challenging. Here, we propose a performance control strategy for elastomers inspired by the biomechanics of frog jumping, enabling the design of an ultrabroad linear range bimodal force sensor. The sensor can achieve 1.44-MPa wide sensing ranges (0–640 kPa in 0%–15% compress strain and 0–800 kPa in 0%–100% tensile strain) and high linearity (coefficient of determination, $R^{2} =0.9956$ in the 0–640-kPa compress range, $R^{2} =0.9939$ in the 0–310-kPa tensile range, and $R^{2} =0.9914$ in the 310–800-kPa tensile), which also exhibited good response time, cycle stability, and sensitivity. The experiments show that the sensor has remarkable potential application in human and soft robot sensing.