Discrete Femtolitre Pipetting with 3D Printed Axisymmetrical Phaseguides

Area of Science:

• Microfluidics
• Nanotechnology
• Biotechnology

Background:

• Precise pipetting of femtoliter volumes is crucial for nanoscale surface functionalization and single-cell fluid manipulation.
• Pressure-controlled pipetting is versatile but faces challenges in achieving femtoliter precision.

Purpose of the Study:

• To propose and validate a new concept for femtoliter volume pipetting using axisymmetrical phaseguides within microfluidic channels.
• To develop an analytical model for designing femtopipettes and verify it experimentally.

Main Methods:

• Development of a novel femtopipette concept utilizing axisymmetrical phaseguides.
• Fabrication of femtopipettes using a multi-scale 3D printing strategy (digital light processing and two-photon polymerization).
• Design and experimental verification of three femtopipette variants with resolutions of 10 picoliters, 180 femtoliters, and 50 femtoliters.

Main Results:

• Successful fabrication of femtopipettes with distinct pipetting resolutions.
• Experimental validation of the analytical design model for femtopipettes.
• Demonstration of controlled aspiration and dispensing of a water-glycerol mixture into a mineral oil droplet.

Conclusions:

• The proposed phaseguide-based femtopipette offers a precise method for handling discrete, known volumes of liquid at the femtoliter scale.
• Multi-scale 3D printing enables the fabrication of these advanced microfluidic devices.
• This technology has significant potential for applications requiring ultra-precise liquid handling at the micro and nanoscale.