memsstar’s close collaboration with the University of Edinburgh has resulted in the first in series of published MEMS research results using memsstar’s MEMS processing system and coating technology. This first article is entitled; “The effect of micropillar spacing and temperature of substrate on contact angle dynamics.” The idea behind this specific research is to examine the fluid dynamics of droplets on superhydrophobic surfaces. Superhydrophobic surfaces repel water and can be self-cleaning, anti-icing and low friction. Understanding the mechanism behind these interesting properties can allow them to be tailored and enhanced.
For the past 18 months, the University of Edinburgh team has been using memsstar’s ORBIS™ 1000 AURIXTM platform in its MEMS research to deposit self-assembled FDTS film. This film deposits a hydrophobic coating onto the structured Si surfaces, created at the University. University researchers were able to characterize the relationship between surface roughness and contact angle (a measure of a surface’s hydrophobicity) for superhydrophobic and hydrophobic surfaces.
memsstar’s equipment is housed at the University’s Scottish Microelectronics Centre (SMC), which also serves as the company’s MEMS research and development site. The SMC is located in a purpose-built facility at the University of Edinburgh’s Science and Engineering campus at King’s Buildings and consists of approximately 300m2 of class 10 and 250m2 of class 1,000-10,000 cleanrooms and 1000m2 of office and laboratory space.
The partnership began when University researchers requested an on-site demo of the ORBIS system to compare its capability to the wet deposition technology available within the University’s chemistry department. It was determined that the vapour deposition method generated overall better results. memsstar provided the University team with process support, while the researchers performed experiments and analysis post deposition.
The primary benefit in using the ORBIS AURIX platform on this specific technology is its speed. Typical wet chemistries take some time—up to 48 hours—for the self-assembled monolayer (SAM) coating to fully bond and form; the memsstar deposition takes less than 10 minutes per wafer. When part of an ORBIS 3000 platform, where there are additional process modules, this can allow for MEMS products to be both released and treated with an anti-stiction film in situ, and without the need to break vacuum, which is where many devices face an issue without the SAM treatment first.
The University’s work can have an important contribution to fluid dynamics, particularly at the solid-liquid interface that has applications in numerous medical and industrial processes. There are currently several projects underway, which aim to examine the relationship between hydrophobic surfaces and fluid dynamics, which use surface structure to enhance the intrinsic hydrophobicity of the memsstar coating.
Read the MEMS research.