Solvent Compatibility of Parylene C Film Layer

Abstract

Parylene C has been preferred in various microfluidic and packaging applications as a chemical barrier; therefore, its durability in chemicals is critical to maintain functionality of the devices. In this paper, we investigated solvent compatibility of Parylene C in a range of solvents with regard to swelling of it and the change in its surface roughness at room temperature. The results of Parylene C swelling were associated with solubility parameter, δ (cal/cm 3 ) 1/2 , which is predicted from the parameters of dispersion, polar, and hydrogen-bonding forces. Solvents that swelled Parylene C film layer mostly were benzene, chloroform, trichloroethylene, and toluene, while methanol, 2-propanol, ethylene glycol, and water did not cause any swelling. Subsequently, the adverse effects of diffusion of solvents through a Parylene C film layer were demonstrated by stripping of the encapsulated photoresist. In addition, a comparison was made between Parylene C and poly(dimethyl)siloxane (PDMS) considering the data of swelling ratios obtained from the experimental findings and the literature, respectively. Experimental findings showed that Parylene C is much more compatible to solvents than PDMS in high-throughput microfluidic and packaging applications. These results will be of great value to scientists for understanding compatibility of any selected solvent on Parylene C in the applications of micro devices.[2013-0113]

Micromachining of Parylene C for bioMEMS

“…Lastly, although the water and vapor permeability may be lower than other materials, soaking of Parylene C films results in water vapor penetration and ion permeation . A similar phenomenon is observed during solvent soaking, as Parylene C swells to a degree largely determined by solvent type, molecular size of the solvent, and thickness of the film . Consideration of these effects is key in the development of fabrication processes as well as choice of sterilization techniques for Parylene C or Parylene C‐coated biomedical devices .…”

Resonant magnetoelastic microstructures for wireless actuation of liquid flow on 3D surfaces and use in glaucoma drainage implants

“…Finally, Parylene-C, with which the actuators are coated, exhibits excellent long-term stability and efficacy as a biocompatible material 62 . It does not exhibit any swelling in aqueous environments 67 . As a result, Parylene-C-coated magnetoelastic actuators are expected to remain stable in vivo.…”

In situ vapor-deposited parylene substrates for ultra-thin, lightweight organic solar cells

“…Films may swell and roughen upon exposure to certain solvents, though no permanent damage has been observed. 38 In addition, parylene-C absorbs at wavelengths below λ = 290 nm (Fig. S2, SI) and can suffer from UV photodegradation in the presence of oxygen.…”