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, specifically looking at frequency and amplitude. A novel method was developed using an automatic device to record hair movement with a high-speed camera, analyzing the effects of different driving amplitudes and frequencies. The study also quantified the impact of chemical treatments like oxidative bleaching and hair relaxing on hair movement. Key findings included the determination of natural frequency and damping factors for various hair qualities during the damping period after the driving force ceased.