Casado Santiago
Madrid Institute for Advanced Studies in Nanoscience (IMDEA Nanoscience), Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
Beilstein J Nanotechnol. 2017 Jan 16;8:159-166. doi: 10.3762/bjnano.8.16. eCollection 2017.
Controlling the stick-slip friction phenomenon is of major importance for many familiar situations. This effect originates from the periodic rupture of junctions created between two rubbing surfaces due to the increasing shear stress at the interface. It is ultimately responsible for the behavior of many braking systems, earthquakes, and unpleasant squeaky sounds caused by the scratching of two surfaces. In the case of a musical bow-stringed instrument, stick-slip is controlled in order to provide well-tuned notes at different intensities. A trained ear is able to distinguish slight sound variations caused by small friction differences. Hence, a violin can be regarded as a perfect benchmark to explore the stick-slip effect at the mesoscale. Two violin bow hairs were studied, a natural horse tail used in a professional philharmonic orchestra, and a synthetic one used with a violin for beginners. Atomic force microscopy characterization revealed clear differences when comparing the surfaces of both bow hairs, suggesting that a structure having peaks and a roughness similar to that of the string to which both bow hairs rubbed permits a better control of the stick-slip phenomenon.
控制粘滑摩擦现象在许多常见情况下都至关重要。这种效应源于两个摩擦表面之间由于界面处剪切应力增加而产生的周期性连接破裂。它最终导致了许多制动系统的行为、地震以及两个表面刮擦产生的令人不悦的吱吱声。在弓弦乐器的情况下，会控制粘滑现象以在不同强度下提供音调精准的音符。训练有素的耳朵能够辨别由微小摩擦差异引起的轻微声音变化。因此，小提琴可被视为在中尺度上探索粘滑效应的完美基准。研究了两根小提琴弓毛，一根是专业爱乐乐团使用的天然马尾毛，另一根是初学者小提琴使用的合成弓毛。原子力显微镜表征显示，比较两根弓毛的表面时存在明显差异，这表明具有与两根弓毛所摩擦的琴弦相似的峰值和粗糙度的结构能够更好地控制粘滑现象。
