FENG, X.; Cheng, L. K. W.; LIN, X.; Wu, A. R.

Microfluidics chips have emerged as significant tools in cell culture due to their capacity for supporting cells to adopt more physiologically relevant morphology in 3D compared with traditional cell culture in 2D. Currently, irreversible bonding methods commonly used in chip fabrication mean that chips cannot be detached from their substrate without destroying the chip structure, which makes it challenging to do further analysis on cells that have been cultured on-chip. Some reversible bonding techniques exist but are restricted to certain materials, or require complex processing procedures. Here, we demonstrate a simple and reversible polydimethylsiloxane (PDMS)-polystyrene (PS) bonding technique that allows devices to withstand extended operation while pressurized, and supports long-term stable cell cultures. Importantly, it allows rapid and gentle live cell extraction for further downstream manipulation and characterization after long-term on-chip culturing, or even further subculturing. Our new approach could greatly facilitate microfluidic chip-based tissue and cell cultures, overcoming current analytical limitations and opening up new avenues for downstream uses of on-chip cultures, including 3D-engineered tissue structures for biomedical applications.