Optical Tweezers: From Light Scattering Fundamentals to Single-Molecule Manipulation and Cellular Mechanosensing

Abstract

Optical force originates from momentum transfer in the interaction between light and matter, forming the physical foundation of optical tweezers. Over the past four decades, optical tweezers have undergone a paradigm shift from passive manipulation tools to active platforms for bioregulation. This review focuses on the latest advances in the field of optical mechanics, ranging from fundamental theory to biological applications. First, the fundamentals of light scattering in different regimes and the resultant optical forces, as well as the conditions for stable trapping, are described. Then, advanced optical tweezer platforms developed on various physical principles are reviewed. Applications from single-molecule force spectroscopy to optical probing of cellular mechanosensitive responses are discussed. At the end, future directions toward in vivo manipulation, high-throughput automation, and intelligent real-time feedback control are provided.