Journal Article Research Support, Non-U.S. Gov't 3D 3D disordered ramie MXenes Research Support, U.S. Gov't, Non-P.H.S. cardiovascular monitoring continuous monitoring of blood pressure energy harvesting flexible piezoelectric sensor harmonic resonator helices hierarchical structures in situ electrochemical infrared spectroscopy low‐temperature molten salt molecular reconstruction nanogenerator nanogenerators personalized healthcare piezoelectric composite porous ramie carbon stretchable bioelectronics structural stability triboelectric effect triboelectric generators ultrafast and scalable synthesis universality vertical-strip arrays vibration sensor wearable electronics