Stroboscopic detection of multi-colloidal hydrodynamics using time-multiplexed optical tweezers

TL;DR

This paper introduces a stroboscopic optical tweezers system that allows high-speed, multi-colloid manipulation and sensing, enabling advanced studies of colloidal hydrodynamics with improved calibration robustness.

Contribution

The paper presents a novel time-multiplexed optical tweezers system capable of kHz-rate control and sensing of multiple colloids, surpassing traditional camera-based methods.

Findings

Demonstrated arbitrary control of multiple colloids at kHz rates.

Validated the system with simple multi-colloidal experiments.

Showed improved calibration robustness against environmental factors.

Abstract

Time-division multiplexing presents an attractive opportunity to probe multi-colloidal interactions in optical traps at short time-scales. In this paper, we demonstrate a stroboscopic system capable of arbitrary control of multiple trapped colloids with sensing at kHz rates and validate it using several simple multi-colloidal experiments. We expect this methodology will be of benefit in the study of group colloidal hydrodynamics and systems of active colloids, particularly where a temporal sensitivity beyond that of camera-based position sensing is required. In addition, our multiplexing enables calibration that is robust to environmental anomalies, shape distortions of colloids and scattering interference from other particles.