초록 |
Optical laser tweezers have been utilized to quantitatively measure the interaction forces and microrheological properties and to carry out structural manipulation in various soft matter systems, such as biological systems, polymer/biopolymer, and colloidal suspensions. In general, the reflection and refraction of a laser beam at the interface between an object and a fluid medium generate optical forces that can drive the object toward the beam focus. Using the optical laser tweezer apparatus, we investigate physical properties of various colloidal systems, e.g., interactions between polymeric particles in a low dielectric constant medium, critical electrolyte concentrations for colloid adsorption to fluid-fluid interfaces, and aspect ratio-controlled capillary forces between ellipsoidal particles at an oil-water interface. |