Carbon Nanotube Bearing

Eugene Cook, Draper & MIT
Project lead at Draper: David J Carter (PI), Marc Weinberg, Peter Miraglia
Advisor: Prof. Spakovszky

Carbon nanotube rotor [not to scale]

Rotating Micro Electro-Mechanical Systems (MEMS) require rotary bearings, but current MEMS bearing technologies have drawbacks. Silicon rubbing on silicon wears out quickly. Gas bearings require a gas source, and are relatively low stiffness. A promising alternative, proposed and being pursued by the Charles Stark Draper Laboratory in collaboration with the GTL, is to use Carbon Nanotubes (CNTs). Multi-walled CNTs have a concentric-tube structure that lends itself to bearings. Each tube is strong, but there is little or no bonding between tubes, allowing them to slide relative to each other. However, the friction characteristics of these bearings are not precisely quantified. This project’s goal is to construct a simple CNT bearing rotary device, demonstrating MEMS and CNT compatible fabrication techniques, and allowing some data on the friction characteristics to be gathered. Applications of such a bearing technology could include microscale turbomachinery, as well as gyroscopes, pumps, and other rotating devices.