Photovoltaic Rotation and Transportation of a Fragile Fluorescent Microrod Toward Assembling a Tunable Light-Source...

Area of Science:

• Materials Science
• Optoelectronics
• Microelectromechanical Systems (MEMS)

Background:

• Controlling the rotation of fragile, photosensitive microrods is crucial for microelectromechanical systems (MEMS) but remains a significant challenge.
• Existing methods often involve complex setups or risk damaging delicate microstructures.

Purpose of the Study:

• To develop a safe and flexible method for the continuous rotation of fragile, fluorescent microrods.
• To demonstrate precise control over microrod manipulation and assembly for microscale applications.

Main Methods:

• Utilizing a photovoltaic strategy with a continuous wave visible laser (473 nm) at ultralow power (tens of μW) on a LiNbO3/Fe substrate.
• Employing a Gaussian laser profile that does not require full microrod coverage or cause significant temperature increases.
• Analyzing experimental and simulation data to understand the photovoltaic field interactions and torque generation.

Main Results:

• Achieved continuous rotation of microrods driven by electrostatic torque from a localized photovoltaic field.
• Demonstrated controllable movement along complex trajectories and precise orientation control by combining rotation and transportation modes.
• Successfully tuned the end-emitting spectrum and photothermal cutting of microrods via laser illumination configuration.
• Photovoltaic assembly of a tunable microscale light-source system using a microrod emitter and polystyrene microsphere lens.

Conclusions:

• The proposed photovoltaic strategy offers a robust and versatile method for manipulating individual microrods.
• This technique opens new possibilities for fabricating complex microscale devices and systems with tailored optical properties.
• The ability to control microrod rotation, movement, and assembly advances the field of microfabrication and optoelectronics.