Advanced and autonomous applications of optical tweezers

Abstract

The invention of the microscope in the late 16th century revealed a hid den microscopic world, allowing direct observation of structures and or ganisms beyond the limit of human vision. Since then, the importance of this world for human health, materials science, and advanced technology has driven the development of increasingly sophisticated analysis methods. Among these, optical tweezers have become a central tool, using lasers to manipulate and probe objects with exceptional precision enabling single molecule, single-cell, and single-particle studies. Recent years have seen explosive growth in the use of artificial intelli gence (AI), particularly machine learning, across research. In Paper I, we examine how these methods are used in optical tweezers and the likely tra jectory of their integration and give some guidelines. Paper II presents an optical tweezers system with custom electronics, firmware, user interface which together makes the instrument capable of performing experiments fully autonomously. Using this system, we performed four representative experiments, demonstrating both reproducibility and variety of autonomous experiments. In Paper III, the system was applied to probe particle adsorp tion and desorption at liquid–liquid interfaces, revealing previously unseen dynamics of these processes. Finally, Paper IV addresses the challenge of force calibration under non-ideal conditions, in particular low sampling rates and long integration times, and proposes a framework to handle these chal lenges. Together, these works introduce several new techniques for optical tweez ers, spanning colloidal studies, automation, and trajectory analysis. Au tomation in particular will be crucial for the future of optical tweezers by bridging the gap between single-molecule, cell or particle studies and ensem ble measurements, enabling the application of deep learning for advanced modeling and unlocking the potential of optical tweezers for large, data driven studies.