Natural Swing Frequency of Human Hair: A Novel Method to Quantify Natural Hair Collective Movements

The study investigated the movement characteristics of human hair, focusing on the relationship between the structural integrity of inner hair fibers and the movement of hair strands. A novel method using an automatic back-and-forth-hair-movement-device and high-speed camera was developed to analyze hair movement. The study quantified the effects of chemical treatments like oxidative bleaching and hair relaxing on hair movement. It recorded swinging characteristics, including maximal tip amplitudes and phase shifts, and determined natural frequency and damping factors for different hair qualities. This research provided insights into how hair-hair interactions, shape, and alignment influence hair movement.