Living cell manipulation in a microfluidic device by femtosecond optical tweezers

• A microfluidic device was fabricated by water-assisted femtosecond laser ablation.
• The internal surface of the microfluidic device is smooth enough for optical and biological applications.
• Living cells can be moved and sorted in the microchannel by femtosecond optical tweezers.
• The incorporation of the femtosecond optical tweezers and the microfluidic chips is practical in cell sorting.

We have realized cell sorting and manipulation in a fabricated microfluidic device by a self-constructed femtosecond optical tweezer efficaciously. The used microfluidic device with two micro-pools inside silica glass is fabricated by water-assisted femtosecond laser ablation and subsequent heat treatment. After the heat treatment, the diameter of the fabricated microchannels could be reduced significantly and the internal surface of the device could also be made much smoother comparatively, which was crucial for the subsequent experiments of living cell manipulation and cell sorting by using femtosecond optical tweezers because of the optical beam quality required. Our experimental results show that we can manipulate cells very easily by our self-constructed femtosecond optical tweezer, which demonstrates that the incorporation of the microfluidic device and the femtosecond optical tweezer is accessible and practical for the micromanipulation experiments, such as cell sorting and manipulation.