Fig. 6: Liquid metal strain sensors (LMSS) for human motion detection.

Physiological signal monitoring. a resistance signals (ΔR/R₀) of radial artery pulses with the maximum strain (ε_max) estimated from the sensing characteristic curve. b Magnified view of a single pulse from (a), with three characteristic peaks identified as the percussion wave (P), tidal wave (T), and diastolic wave (D). c Carotid artery pulses, and d magnified view of a single resistance pulse from (c). Vocal vibration monitoring: e resistance signal during the pronunciation of “Liquid Metal” and f magnified view of the resistance signal from a single pronunciation. Facial micro-expression monitoring: g blinking, h eyebrow raising, and i smiling. Joint bending monitoring: j index finger bending, k elbow flexion, and l knee flexion. Physical activity monitoring: m jumping in place, knee-bend jumping, marching in place, high-knee running in place, and walking. Insets show photographs of the strain sensor attached to various locations on the human body. Source data are provided as a Source data file.