Synthetic polymer materials cannot fully meet the biocompatibility and high biological functional requirements required as biomedical materials. To address these issues, low-temperature plasma surface modification technology has been widely used in biomedical materials due to its unique advantages. After plasma treatment, bioactive molecules can be immobilized on the surface of polymer materials, achieving the goal of being used as biomedical materials.
Microfluidic Chip
Polydimethylsiloxane (PDMS) is a high-performance polymer with excellent properties such as good transparency, unique elasticity, good encapsulation, simple fabrication process, low raw material cost, and non-toxic insulation, making it widely used in the fields of medicine, microfluidic systems, and flexible electronics.
However, due to the high hydrophobicity and strong adsorption of polar substances on the surface of cured PDMS, it cannot bond with other materials (such as glass and silicon wafers) without surface treatment, which greatly limits its application in various fields. Plasma treatment is the most commonly used bonding technology in the fabrication of microfluidic chips.
Oxygen plasma bonding technology uses an oxygen plasma surface treatment instrument to treat PDMS and other silicon-based materials separately, and then forms an irreversible bond between the treated PDMS and silicon-based materials. The basic principle of the oxygen plasma surface treatment instrument is to use sufficient energy to convert oxygen gas into a plasma state in the chamber, and then use the properties of the active components of oxygen in the plasma state to treat the surface of PDMS and silicon-based materials, thereby achieving the purpose of surface modification. After surface modification, an irreversible bond can be formed between PDMS and silicon-based materials.
PDMS bonding with glass
As shown in the figure, after surface modification by oxygen plasma treatment, the -CH groups in the chemical formula on the surface of PDMS are replaced by -OH groups, which have hydrophilicity and form Si-OH bonds, making the modified PDMS surface highly hydrophilic. Similarly, after modification by an oxygen plasma surface treatment instrument, the -ONa groups in the chemical formula on the surface of the glass are replaced by -OH groups, forming Si-OH bonds. When the modified PDMS and glass surfaces are placed in contact with each other, the following condensation reaction occurs between the Si-OH bonds on their surfaces: Si−OH+HO−Si→Si−O−Si+2H20.
After the condensation reaction between the PDMS and glass surfaces, a strong Si-O-Si bond is formed between them, which realizes the irreversible bonding between PDMS and glass.
Tissue Culture Dish
At present, disposable plastic Petri dish are widely used in many fields such as biology, medicine and chemical industry. Plastic products have become the preferred polymer materials for experimental analysis in industries such as biology and medicine due to their low prices. However, the surface of cell Petri dish in the prior art, such as polystyrene (PS), polyethylene (PE), polycarbonate (PC), etc., are not hydrophilic, so it is very difficult to use them for cell adherent culture.
The reaction gas is introduced into the plasma surface treatment equipment. The reaction gas ionizes the active groups, including amino and carboxyl groups, in the plasma surface treatment equipment. The active groups carry out hydrophilic modification on the surface of the cell Petri dish. Complex chemical reactions will occur on the surface of the activated material. The introduction of new functional groups can significantly improve the surface activity of the cell Petri dish, Effectively improve the surface hydrophilicity of cell Petri dish.
