Controlled Suppression of Wear on the Nanoscale by Ultrasonic Vibrations

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• 作者：Patricia Pedraz ; Reinhold Wannemacher ; Enrico Gnecco
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：September 22, 2015
• 年：2015
• 卷：9
• 期：9
• 页码：8859-8868
• 全文大小：693K
• ISSN：1936-086X

文摘

Wear on the nanoscale, as evidenced by the formation of periodic ripples on a model polystyrene thin film while a sharp tip is sliding on it with a normal force in the 渭N range, is shown to be suppressed by the application of ultrasonic vibrations of amplitude A_exc. An accurate calibration of the transducer excitation amplitude is achieved by a home-built setup based on a laser Doppler vibrometer. The corrugation of the typical ripple pattern that is formed in the absence of vibrations is reduced when the excitation frequency matches the contact resonance of the system and A_exc progressively increases. Above a critical value of A_exc, the ripples completely disappear, while the friction levels off at a finite value determined by the normal force and the vibration amplitude. This value can be significantly smaller than the value of the macroscopic friction coefficient. In addition to the control of wear in general, this opens up the possibility of controlled nanolithography with improved accuracy.