ABSTRACT
If one wishes to build a physical structure or a chemical process, then an understanding of the mechanical properties of the materials is essential. Biologists and clinicians want to understand how natural materials are made, how they work, and why they sometimes fail. While an engineer might use a macroscopic tool to study hard building materials, biologists require a microscopic device to study soft biological cells and molecules. The reason that optical tweezers have found so many applications in biology is that they are just right for grabbing and manipulating soft biological materials [1,2].
