Tiny Tools Solve Major Carving Problems

Author:  Raechel Zipagan
Institution:  Boston University
Date:  November 2004

Miniature tools, barely visible to the naked eye, are solving pattern-carving problems in glass, ceramics, and other brittle materials, a group of researchers reported in the upcoming December issue of the Journal for Micromechanics and Microengineering.

When brittle materials are machined into microscopic patterns, they typically come apart in large pieces or crack completely. Miniature tools can create well-defined, accurate microscopic patterns in brittle materials without cracking them. Carving tiny patterns in glass is especially important for making small channels to flow through, controlling chemical reservoirs.

"Even very brittle materials like glass will cut smoothly at a micron level," explained Eric Marsh, an associate professor of Mechanical Engineering at Pennsylvania State University. "The tools we are making are small enough so that the brittle materials behave like a malleable material like aluminum, producing smooth curly chips of glass or ceramic."

Marsh and his colleagues created miniature drills and end mills by removing microscopic pieces from a form of diamond. The places where the pieces are removed are rough, turning the diamond into a cutting tool.

These tiny tools can carve shapes that current micro-scale carving processes cannot. Traditionally, surface shapes have to be built up layer by layer, creating a stair-step surface. The tiny tools grind and shape smooth surfaces, removing stair-step patterns that can get in the way of micro-scale work.

"This really is a way to get shapes that we cannot get any other way," says Marsh.

The researchers are currently using existing machines designed for larger equipment to operate the tools, but they hope to develop a tabletop machine in the future.