Manipulation of micro-objects using acoustically oscillating bubbles based on the gas permeability of PDMS

Area of Science:

• Microfluidics
• Acoustic manipulation
• Biotechnology

Background:

• Micro-object manipulation is crucial for various applications, including cell sorting and drug delivery.
• Existing methods often require complex setups, high temperatures, or electrochemical reactions.
• Developing efficient, non-invasive micro-manipulation tools is an ongoing challenge.

Purpose of the Study:

• To present a novel on-chip method for manipulating micro-objects using acoustically oscillating bubbles.
• To demonstrate precise control over bubble position and micro-object handling.
• To validate the method's efficiency and non-invasive nature for biological and material applications.

Main Methods:

• Utilized acoustically oscillating bubbles within a polydimethylsiloxane (PDMS) microfluidic device.
• Controlled bubble position by modulating gas permeability and generating pressure differences.
• Demonstrated microparticle (10 μm polystyrene) capture, transport, and release.
• Investigated the influence of acoustic frequency and pressure difference on manipulation performance.

Main Results:

• Successfully captured, transported, and released 10 μm polystyrene microparticles.
• Demonstrated controllable movement of the air-liquid interface via pressure differences.
• Achieved complete manipulation (capture, transport, release) in under 1 minute.
• Confirmed the non-invasive nature, avoiding high temperatures or electrochemical reactions.

Conclusions:

• The proposed acoustically driven bubble manipulation is a controllable, efficient, and non-invasive technique.
• This method offers a promising tool for on-chip selection and handling of micro-objects like cells and particles.
• The rapid manipulation speed and gentle handling make it suitable for sensitive biological samples and microfluidic applications.