Indirect optical trapping using light driven micro-rotors for reconfigurable hydrodynamic manipulation

Abstract

Optical tweezers are a highly versatile tool for exploration of the mesoscopic world, permitting non-contact manipulation of nanoscale objects. However, direct illumination with intense lasers restricts their use with live biological specimens, and limits the types of materials that can be trapped. Here we demonstrate an indirect optical trapping platform which circumvents these limitations by using hydrodynamic forces to exert nanoscale-precision control over aqueous particles, without directly illuminating them. Our concept is based on optically actuated micro-robotics: closed-loop control enables highly localised flow-fields to be sculpted by precisely piloting the motion of optically-trapped micro-rotors. We demonstrate 2D trapping of absorbing particles which cannot be directly optically trapped, stabilise the position and orientation of yeast cells, and demonstrate independent control over multiple objects simultaneously. Our work expands the capabilities of optical tweezers platforms, and represents a new paradigm for manipulation of aqueous mesoscopic systems.

Magnetically Driven Bionic Millirobots with a Low-Delay Automated Actuation System for Bioparticles Manipulation

“…However, applied vibration decreased the time for response and positioning accuracy (mean error = 9.3 µm). The effect of the friction reduction of the piezoelectric ceramics was confirmed by the second experiment results that are shown in Figure 8a-c. As shown in Figure 8a, the experiment involved actuating the robot over a square patter (8 steps) with its 4 corners being in (9,9), (10,8), (11,9), (10,10). The piezoelectric ceramics were connected to a wave generator (10 Vpp, sinusoidal signal, frequency within [1 kHz; 15 kHz]; offset = 0 V, phase 0 • ) and a voltage amplifier (voltage within [0; 4]) which allowed us to provide a voltage ranging from 0 V to 80 V to the ceramics.…”

“…Chunlin Zhao et al used a programmatic control method of cell oocyte nuclear injection to increase the blastocyst rate effectively [6]; Xinyu Liu presented a vision-based cellular force sensing approach, including a microfabricated elastic cell holding device and a sub-pixel visual tracking algorithm which can decrease forces to 3.7 nN during microrobotic mouse embryo injection [7]. In addition, many driving methods such as chemical reaction [8], acoustic waves [9], optoelectronics [10] and the magnetic field [11], are chosen for different reasons to manipulate microrobots. Among them, the magnetic field is a safe and powerful tool for its biocompatible and broad output force range [12].…”

Plasmonic Tweezers towards Biomolecular and Biomedical Applications

“…Multiple trapping sites can be achieved and the distances among them can be modified dynamically through various optical methodologies for OTs [98,99]. Using this feature, interactions between the trapped micron biological particles have been examined and the micron robot has been assembled [100,101]. Unlike conventional OTs, the distance among different trapping sites is fixed for PTs after the fabrication process.…”

Single-Cell Elasticity Measurement with an Optically Actuated Microrobot

“…Furthermore, microtools have been developed to control the flow of the solvent that carries these biological objects [ 6 , 7 ] or to characterize their composition [ 8 ]. The complexity of microrobots spans from simple microspheres [ 1 , 9 ] to complex tailor-made microstructures [ 4 , 10 , 11 , 12 ], and sometimes a group of such structures is needed to perform specific tasks [ 13 , 14 ]. Most often, these microtools are actuated and guided by optical means, but magnetic [ 15 , 16 ] or acoustic [ 17 ] controls are also applied.…”