In recent years, with the rapid development of biomedical technology, higher requirements have been placed on the reliability and biocompatibility of medical devices and implantable devices. Under this background, Parylene coating has become one of the key materials in the biomedical field due to its excellent performance.

Characteristics of Parylene Coating

Parylene is a high-performance polymer coating of poly-para-xylylene, which forms an ultra-thin and uniform protective coating through chemical vapor deposition (CVD) technology. Its superior performance makes it an ideal choice for many medical devices and electronic devices. The following are several key characteristics of Parylene coating:

1. Biocompatibility

Parylene has passed multiple biocompatibility tests (such as ISO 10993 and USP Class VI certification), is non-toxic and harmless to human tissues and body fluids, and is widely used in implanted and in vitro devices.

2. Chemical inertness

Parylene has extremely high tolerance to a variety of chemicals and can effectively resist corrosion and chemical degradation, especially in complex in vivo environments.

3. Insulation

Its excellent electrical insulation properties make it an important material for protecting microelectronic devices and implantable medical devices to prevent short circuits and current leakage.

4. High gas barrier

Parylene coating has super strong barrier ability to gases such as water vapor and oxygen, which can extend the service life of the device and protect core components.

5. Ultra-thinness and uniformity

Parylene coating can be as thin as micrometer level (less than 5 μm) and can cover complex geometric shapes, ensuring the precision and flexibility of the equipment.

Main applications of parylene coating in the biomedical field

1. Protection of implantable medical devices

Parylene coating is widely used for the outer surface protection of implanted devices such as pacemakers, brain-computer interfaces, and cochlear implants. Its superior biocompatibility and barrier properties can effectively prevent body fluids from corroding the device, while avoiding adverse effects of the device on human tissue. For example, parylene coatings used in neurostimulators can provide long-term stable insulation and protection to ensure the safety and reliability of the device.

2. Micro medical sensors

With the development of microelectromechanical systems (MEMS) technology, micro sensors are increasingly used in biomedical testing. Parylene coatings can protect the delicate circuits inside the sensor from moisture and chemicals in the environment while maintaining the high sensitivity of the sensor.

3. Catheter and surgical instrument coatings

For catheters, minimally invasive surgical instruments, etc., the chemical inertness and smooth surface of parylene coatings can reduce friction, reduce the difficulty of surgical operations, and prevent the adhesion of blood and other body fluids, reducing the risk of infection.

4. Wearable devices and diagnostic devices

Parylene coating can improve the durability of wearable devices and in vitro diagnostic devices, especially when the device needs to be exposed to sweat, water or drug solutions, its excellent waterproof performance is an ideal choice.

5. Drug delivery and microneedle technology

In drug delivery systems, parylene can be used as a surface protective layer for microneedles or drug carriers to ensure the stability of the device during transportation and implantation, while avoiding unnecessary chemical reactions.