Micro gas bearings fabricated by deep X-ray lithography

Micro bearing systems for Micro Electromechanical Systems (MEMS) have drawn attention for several decades as critical components for micro rotating machinery. Ideally, frictionless bearings are needed, and in practice, micro gas bearings approach the ideal. Typically, bearings function as a separate component, assembled onto sliding counterparts. However, in micro scale devices, assembly procedures are known to be very tedious and time consuming. This leads to the pursuit of single material monolithic structures. Critical issues arising from these approaches include: limitation of materials, friction, and reliability, among others. In this paper, new approaches have been pursued. Micro gas bearings were fabricated as a single component through X-ray lithography. A stainless steel gauge pin, machined to ultra precision, was used as a journal shaft. Simple and very easy assembly processes using self-aligning concepts were developed as an alternative method to conventional assembly. This article presents the design, fabrication, assembly, and testing of micro gas bearings.