(234c) Nanotribological Properties of Gas-Phase Lubricants between Silicon Nano-Asperity Contacts

Adhesion, friction, and wear in MicroElectroMechanical System (MEMS) devices are key challenges limiting MEMS technology. Typically made of polycrystalline silicon, these devices need a self-healing or replenishing lubricant layer to prevent wear, reduce adhesion, and minimize friction. The adsorption isotherm of gas-phase alcohol lubricant molecules provides the formation of molecular-thick films on silicon oxide surfaces. The presence of these films on silicon surfaces lowers both the adhesive and frictional response between native silicon oxide nano-asperity contacts. Tribological properties of alcohol vapor films are investigated as a function of chain length (C2 ? C5) on silicon contacts. Surface chemistry pertinent to this system is discussed.