Micro-Rheology Measurements with the NanoTracker

_{KEYWORDS: Optical Tweezers; Optical Trapping;  NanoTracker; Force Measurements; Rheology; Viscoelastic Properties; Nanomanipulation; Life Science}

Bruker's NanoTracker optical tweezers system is a versatile high resolution force measurement tool. It is based on the principle of optical trapping and uses the interactions between light and refractive particles to generate and measure forces on these particles in the range of a single piconewton to hundred of piconewtons. Among many applications including single molecule force spectroscopy and biomechanical measurements of individual cells and their components, this system provides excellent options to prove the mechanical properties of materials on a local, microscopic scale and relate their viscous, elastic, and viscoelastic contributions to their macroscopic behavior.

Micro-rheology finds wide applications in material science and soft matter physics. In this app note, the principles of optical tweezers as a force measurement tool, micro-rheological measurements, and example applications of data acquisition with the NanoTracker are presented.

Readers can expect to learn about:

• Various types of micro-rheology experiments such as viscous drag, elasticity, active and passive rheology measurements;
• Experimental configurations and detailled discussion of these types of measurements showing the easy operation and outstanding performance of Bruker's NanoTracker system; and
• The potential of the NanoTracker together with dedicated accessories as a powerful tool to investigate micro-rheological properties of soft samples under different environmental conditions.