Design and engineering of low-cost centimeter-scale repeatable and accurate kinematic fixtures for nanomanufacturing equipment using magnetic preload and potting

Abstract

This paper introduces a low-cost, centimeter-scale kinematic coupling fixture for use in nanomanufacturing equipment. The fixture uses magnetic circuit design techniques to optimize the magnetic preload required to achieve repeatability on the order of 100 nanometers. The fixture achieves accuracy to within one micrometer via an adjustable interface composed of UV curing adhesive between the mating kinematic coupling components. The fixture is monitored by a micro-vision system and moved by a six-axis nanopositioner until proper alignment is achieved, at which point the fixture position is permanently set by UV light. This thesis presents design rules and insights for design of a general accurate and repeatable kinematic fixture and presents a case study of fixtures used for tool exchange on dip pen nanolithography machines. A prototype fixturing assembly was fabricated and tested for repeatability and stability in six degrees of freedom. The test results concluded that the fixture has a 1-o- 3-D translational repeatability of 87 nanometers and a 3-D stability of 344 nanometers over 48 hours. This is an order of magnitude improvement on past low-cost accurate and repeatable fixture designs. This optimized accurate and repeatable kinematic fixture will enable repeatable, accurate, quick, and elegant tool change, thus advancing the manufacturing capabilities of nanofabrication techniques.