Simultaneous orientation and positioning control of a microscopic object using robotic tweezers

Abstract

Existing control techniques for optical trapping of cells or micro-objects can only perform either positioning control or separate control of orientation and position in a sequential manner. In this paper, we propose a robotic control technique to achieve simultaneous orientation and positioning control of a microscopic object using multiple laser-driven fingertips and robotic motorized stage control. Several optically trapped micro-particles are first utilized as the laser-driven fingertips to grasp a target micro-object. Simultaneous control of the laser-driven fingertips and the robotic motorized stage is then performed to achieve the control objective, in which the target object is oriented to a desired angular position by controlling the laser-driven fingertips, and at the same time, it is manipulated to follow a desired trajectory by maneuvering the robotic stage. Rigorous mathematical formulation and solution are developed for simultaneous orientation and positioning control of a micro-object using optical tweezers.