Micromachined electrochemical T-switches for cell sorting applications

Area of Science:

• Biomedical Engineering
• Microfluidics
• Cell Sorting Technology

Background:

• Conventional cell sorting methods like flow cytometry can damage cells due to high voltages.
• There is a need for gentle, low-power cell sorting techniques compatible with microfluidic systems.

Purpose of the Study:

• To develop and demonstrate a novel MEMS micro-T-switch system for cell sorting.
• To utilize an electrolysis-bubble actuator for low-voltage, room-temperature cell manipulation.
• To assess cell viability and recovery after sorting using the developed micro-T-switch chip.

Main Methods:

• Design and microfabrication of a T-shaped microchannel with a movable micro-T-switch.
• Actuation of the micro-T-switch using an electrolysis-bubble generator.
• Cell sorting experiments using human hepatoma cells.
• Assessment of cell viability via fluorescence assay and post-sorting cell culture.

Main Results:

• Successful demonstration of active-binary switching function for cell sorting.
• Low actuation voltage (3.0–3.5 V) and room temperature operation achieved.
• High cell viability (84.1%) observed in sorted human hepatoma cells.
• Significant cell recovery and colony formation (70.2%) after sorting.

Conclusions:

• The MEMS micro-T-switch actuated by electrochemical bubbles is a viable technology for gentle cell sorting.
• The system minimizes cell damage, offering an alternative to high-energy separation instruments.
• The demonstrated high cell viability and recovery support its potential for biological research and clinical applications.