Page 30 - 《摩擦学学报》2021年第5期

第 41 卷 第 5 期 摩 擦 学 学 报 Vol 41 No 5
2021 年 9 月 Tribology Sept, 2021

DOI: 10.16078/j.tribology.2020137

微液滴在PDMS软基体表面的动态摩擦

行为研究

*
董聪慧, 张亚锋 , 汤 程, 余家欣
(西南科技大学 制造过程测试技术教育部重点实验室, 四川 绵阳 621010)

摘 要: 通过固液界面摩擦力测试装置研究了微液滴在PDMS软基体表面运动时的动态摩擦学行为，并对微液滴体
积、滑动速度及软基体力学性能对固液界面动态摩擦行为的影响进行了分析. 结果表明：微液滴在软基体表面运动
时表现出最大静摩擦力和动态摩擦力. 最大静摩擦力与微液滴黏度和速度梯度呈正比，动态摩擦力与微液滴体积、
滑动速度和基体力学性能有关. 随着微液滴体积的增加，三相接触线长度增加，动态摩擦力增加；随着相对滑动速
度增加，三相接触线长度及接触角滞后增加，动态摩擦力增加；随着软基体弹性模量降低，固液界面黏附力增加，固
液界面运动能量耗散增加，动态摩擦力增加. 研究结果可为PDMS软基体表面微液滴的精确驱动和运动参数优化提
供理论指导，也可进一步丰富固液界面摩擦理论.
关键词: 动态摩擦力; 体积; 滑动速度; PDMS; 弹性模量
中图分类号: TH117.1 文献标志码: A 文章编号: 1004-0595(2021)05–0619–08

Dynamic Frictional Behavior of Microdroplets on

PDMS Soft Substrate

*
DONG Conghui, ZHANG Yafeng , TANG Cheng, YU Jiaxin

(Key Laboratory of Testing Technology for Manufacturing Process, Ministry of Education, Southwest
University of Science and Technology, Sichuan Mianyang 621010, China)
Abstract: The dynamic frictional behaviors of microdroplets on PDMS surface were studied by a self-made frictional
force testing device. The effect of droplet volume, slip velocity, and mechanical properties of the PDMS substrate on the
dynamic frictional behaviors were investigated. Results showed that the solid/liquid interfacial friction force consisted of
maximum static friction force and dynamic friction force. The maximum static friction force was proportional to the
viscosity and velocity gradient. The dynamic friction force was related to the droplet volume, sliding velocity and
mechanical properties of the substrate. The dynamic friction force increased with droplet volume due to the increasing of
the length of contact line. Moreover, the dynamic friction force increased with sliding velocity because the length of
contact line and contact angle hysteresis increased with sliding velocity. Furthermore, solid/liquid interface adhesion
force increased with decreasing of elastic modulus. As a result, the energy dissipation and dynamic friction force
increased. The results would be helpful to provide theoretical guidance for the precise driving of microdroplets and
optimize the motion parameters of droplet on PDMS surface, and then further to enrich the solid-liquid interface friction
theory.
Key words: dynamic friction force; volume; slip velocity; PDMS; elastic modulus

Received 30 June 2020, revised 14 December 2020, accepted 16 December 2020, available online 28 September 2021.
*Corresponding author. E-mail: studentzyf1@163.com ,Tel：+86-816-6089685.
The project was supported by the National Natural Science Foundation of China (51605402), Sichuan Science and Technology
Program (2020YJ0124) and Postgraduate Innovation Fund Project by Southwest University of Science and Technology (20ycx0065).
国家自然科学基金项目(51605402), 四川省科技厅项目(2020YJ0124)和西南科技大学研究生创新基金(20ycx0065)资助.