Automated electrokinetic stretcher for manipulating nanomaterials.

Area of Science:

• Biophysics
• Nanotechnology
• Microfluidics

Background:

• Precise manipulation of nanoscale objects is crucial for studying their properties.
• Existing methods for trapping and stretching often lack automation and high throughput.
• Electrokinetic phenomena offer a promising route for label-free manipulation in solution.

Purpose of the Study:

• To develop and demonstrate an automated platform for trapping and stretching individual micro- and nanoscale objects.
• To enable high-throughput analysis of deformable nanoscale materials.
• To showcase the platform's capability for complex manipulation protocols.

Main Methods:

• Utilizing electrokinetic forces to create a planar elongational field for trapping.
• Employing microfluidic device for controlled fluid flow and electric field application.
• Automated tracking of trapped objects and real-time data acquisition.

Main Results:

• Successfully trapped polystyrene beads (<100 nm) and DNA molecules for extended periods (minutes) with high positional stability (<1 μm).
• Achieved high-throughput stretching of over 400 DNA molecules in approximately 4 hours.
• Demonstrated sequential stretching and multiple stretch-relaxation cycles on individual DNA molecules.

Conclusions:

• The developed automated electrokinetic platform provides a robust method for trapping and manipulating nanoscale objects.
• This high-throughput capability facilitates real-time studies of micro- and nanoscale systems, particularly deformable molecules like DNA.
• The platform's flexibility opens avenues for advanced manipulation techniques and investigations in biophysics and nanotechnology.