Programmable Multimodal Optothermal Manipulation of Synthetic Particles and Biological Cells

Abstract

Optical manipulation of tiny objects has benefited many research areas ranging from physics to biology to micro/ nanorobotics. However, limited manipulation modes, intense lasers with complex optics, and applicability to limited materials and geometries of objects restrict the broader uses of conventional optical tweezers. Herein, we develop an optothermal platform that enables the versatile manipulation of synthetic micro/nanoparticles and live cells using an ultralow-power laser beam and a simple optical setup. Five working modes (i.e., printing, tweezing, rotating, rolling, and shooting) have been achieved and can be switched on demand through computer programming. By incorporating a feedback control system into the platform, we realize programmable multimodal control of micro/nanoparticles, enabling autonomous micro/nanorobots in complex environments. Moreover, we demonstrate in situ three-dimensional single-cell surface characterizations through the multimodal optothermal manipulation of live cells. This programmable multimodal optothermal platform will contribute to diverse fundamental studies and applications in cellular biology, nanotechnology, robotics, and photonics.

Recent Progress on Optical Micro/Nanomanipulations: Structured Forces, Structured Particles, and Synergetic Applications

“…49 Also, the thermal effect can also work synergically with optical forces to manipulate particles. 86,119 As shown in Figure 3c, 119 in the polystyrene glycol/phosphatebuffered saline solution, the laser spot on the light-absorbing substrate coated with bovine serum albumin generates nonuniform temperature distribution. Particles near the spot will be exerted on three forces including the depletion force, thermophoretic force and electrokinetic force.…”

“…Besides working alone, the thermal heating effect can also work together with other forces to manipulate particles. 49,86 Additional physical fields, such as fluidic field 50,51 and electric field, 49,85,119,137,152 can also be generated through heating to manipulate particles. Overall, the utilization of thermal effects affords additional degrees of freedom for more powerful and interesting optical manipulations.…”

“…The particles with surface charge can be then manipulated by Coulomb force and the system manages to trap the particles with modified surface charges in a location very near to the substrate, which is called opto-thermoelectric nanotweezers . Also, the thermal effect can also work synergically with optical forces to manipulate particles. , As shown in Figure c, in the polystyrene glycol/phosphate-buffered saline solution, the laser spot on the light-absorbing substrate coated with bovine serum albumin generates nonuniform temperature distribution. Particles near the spot will be exerted on three forces including the depletion force, thermophoretic force and electrokinetic force.…”

“…(c) Programmable particle motion modes through multiphysical field forces induced by thermal effect controlled by light. Adapted with permission from ref . Copyright 2022 American Chemical Society.…”

“…Utilizing all-dielectric structures to eliminate the optical absorption and avoid heating is one direction. − ,, Different from the methods which mitigate absorption and avoid heating, another direction is to utilize the heating effect. , As stated in the theoretical section, light-induced heating effects can provide additional mechanisms to manipulate particles, such as photophoresis and thermophoresis. , Through tailoring the temperature distribution or engineering the particle’s thermal properties on the surface, particles can be trapped or pulled/levitated as demanded. Besides working alone, the thermal heating effect can also work together with other forces to manipulate particles. , Additional physical fields, such as fluidic field , and electric field, ,,,, can also be generated through heating to manipulate particles. Overall, the utilization of thermal effects affords additional degrees of freedom for more powerful and interesting optical manipulations …”