Fabrication and Characterization of Microparts by Mechanical Micromachining: Precision and Cost Estimation

Abstract

The demands of mechanical micromachining technology have been increased in the manufacturing of micro-scale precision shapes and parts. Mechanical micromachining with microcutting tools has great advantages in productivity, usability, and economical efficiency compared with microelectromechanical system (MEMS) techniques. The main purpose of the present research is to verify the precision and cost efficiency of the mechanical micromachining. In order to measure the precision and feasibility of mechanical micromachining, various microfeatures were machined. Aluminium moulds were machined by the three-axis microstage in order to fabricate a microchip with a 200 μm wide channel for capillary electrophoresis; then the microchips were made by injection moulding with a tolerance of 5 μm. To evaluate the cost efficiency of various micromanufacturing processes, cost estimation for mechanical micromachining was conducted, and costs of microchips fabricated by mechanical micromachining, injection moulding, and MEMS were compared. As a result, it is proved that injection moulding has about 15 times lower cost than the MEMS method in the fabrication of the microchip. Mechanical micromachining is a simple, rapid, and cost-effective method to fabricate the metal master for polymer microchips, which would be suitable for prototypes of microchips.