Parylene: Protecting Life-Enhancing Medical MEMS Technologies
Posted by Sean Horn
Wednesday, January 15, 2014 11:07
@ 11:07 AM
Driving development of such emerging areas as microfluidics, advanced bio-sensing, capsule endoscopy, and personalized medicine, microelectromechanical systems (MEMS) are enabling an array of breakthroughs that promise to enhance patient care and outcomes. Protecting sensitive MEMS products from the harsh conditions both inside the body and out is Parylene conformal coating, which is helping to bring these futuristic technologies to fruition.
Parylene boasts a range of desirable features and properties suited for use in medical MEMS applications, including biocompatibility. Equipped with excellent moisture, chemical, and dielectric barrier properties, Parylene offers uniform protection of the sensitive electronics from medical applications in environments ranging from inside the body to the lab to the rugged, remote terrain in some developing nations. Of course, among the conformal coating’s greatest attributes is that it adds negligible weight and thickness to the lightweight, compact medical devices enabled by MEMS technology.
Among the many innovations enabled by MEMS is capsule endoscopy. Providing an alternative to colonoscopies and EGDs, a pill-sized camera featuring MEMS technology allows for imaging of the GI tract without the need for invasive procedures. Other MEMS-based ‘smart pills’ can assist in targeted drug delivery.
As you can imagine, smart pills need to be able to handle the harsh conditions that are found inside the human body, including corrosive digestive acids that can potentially destroy microelectronics. They also need to be safe for human consumption and not cause any adverse effects to the patient’s biology. With these needs in mind, companies routinely use protective, coatings such as parylene to ensure that MEMS do not become damaged. Parylene has properties that make it an ideal solution for smart pill protection, including being chemically inert, having a low coefficient of friction, and featuring USP Class VI biocompatibility. The coating is also applied in a clear state and remains clear after it has been cured, which is ideal for pills that house micro-cameras or high-precision imaging sensors.
Another popular area in the medical field capitalizing on MEMS is that of portable medical devices, which can be used by patients at home, first responders in the field, battlefield medicine, and clinicians in remote areas of developing nations. Diagnostic and monitoring devices, such as ECGs, blood pressure devices, and even pathogen sensors that test both water and air for viral agents, have leveraged MEMS technology to facilitate portability. With advancements in nanotechnology and MEMS, developers are able to pack increasing technology and performance into decreasing package sizes. As a result, portable medical devices can now contain advanced sensor systems, integrated SoCs, and even HD displays at a scale that mimics most smartphones and tablets.
Because many MEMS-based portable medical devices are exposed to rugged conditions and potentially harsh environments, it is imperative that the sensitive electronics are well protected by conformal coatings such as parylene. Many portable medical devices need to be able to withstand moisture, chemicals, abrasion, and even harsh sterilization processes.
As medical technology continues to decrease in size and becomes mobile, that level of protection offered by conformal coating will ensure that doctors and patients can rely on accurate information when needed, which can mean the difference between life and death.