Low power laser induced microfluidic mixing through localized surface plasmon

Area of Science:

• Optics
• Microfluidics
• Nanotechnology
• Physical Chemistry

Background:

• Microfluidic devices require efficient mixing for various applications.
• Traditional mixing methods can be energy-intensive or complex.
• Localized surface plasmons (LSPs) offer unique optical and thermal properties.

Purpose of the Study:

• To introduce a new optical microfluidic mixing approach.
• To demonstrate mixing driven by surface tension forces sustained by LSP energy.
• To investigate the role of LSP in actuating convective fluid flow.

Main Methods:

• Utilizing gold (Au) nanostructures to support localized surface plasmons.
• Employing non-radiative damping of LSP to generate phonon energy.
• Creating thermal gradients to induce convective fluid flow.
• Conducting experimental validation and computational modeling.

Main Results:

• Localized surface plasmon energy from Au nanostructures generates significant thermal gradients.
• These thermal gradients are sufficient to actuate convective fluid flow via surface tension.
• The method is effective even with a low-power laser source.
• Experimental and modeling results confirm the crucial role of LSP.

Conclusions:

• A novel, low-power optical microfluidic mixing method is presented.
• Localized surface plasmon excitation in gold nanostructures is key to this mixing technique.
• This approach offers a promising pathway for efficient microfluidic mixing.