微尺度下高分子界面粘弹性决定着该界面的粘附和脱附行为，但其测量和表征却十分困难。在本课题中，我们计划利用瞬逝波照明技术，结合磁镊产生高强度的磁场力，控制磁性微米粒子在特定高分子固/液界面附近运动，并实时追踪其三维位置，从而获知和研究微尺度下界面的三维粘弹性质。该方法将直接给出界面粘弹性与距离及外力的关系。另外，我们将通过修饰高分子界面和使用不同的微粒，改变微粒的运动模式，以研究不同胶体和生物体在高分子界面的动态行为，为了解界面粘附和脱附行为提供依据。

The viscoelastic property of the polymer-modified interfaces plays key role in determining the molecule adhesion and detachment at the interfaces. However, the characterization of such interfacial viscoelasticity still remains a challenge. In this proposal, we intend to incorporate a single particle-tracking technique, so-called evanescent wave tracking, with a high-force magnetic tweezers for three dimensional (3D) tracking and manipulations of the probe magnetic beads near liquid/solid interfaces adsorbed with polymers or biomolecules. The 3D interfacial viscoelasticity and force near the surface as a function of the distance can be directly measured. As a result, the dynamic behavior of molecules near polymer-modified interfaces can be mimicked and studied by monitoring the viscoelasticity between probe beads and interfaces modified with the polymers and biomolecules. This novel approach for measuring 3D viscoelasticity at the interface will be a powerful tool for providing an insight understanding on the interfacial behaviors such as adhesion and detachment.