A little pinch: MEMGen's layered fabrication process produced these 24-layer working forceps, including hinges and springs, less than 200 microns thick and about 3mm long. The technique allows for building metal layers to thicknesses upwards of 500 microns.
The EFAB(TM) process fabricates millimeter and submillimeter metal parts and devices with complex geometries and internal features. The high-volume batch production process is similar to 3D rapid prototyping processes, but it uses metals.
In forming parts, the EFAB method stacks independently patterned layers. The patterns are based on a CAD file from any 3D package, notes MEMGen Director of Applications Engineering Nelsimar Vandelli. Metal parts that can be formed by EFAB include surgical tools (see figure), nozzles, switches and relays, antennas, and sensors, among others.
A single machine forms the parts by electroplating them through a mask. According to Vandelli, EFAB differs from other processes (such as surface or bulk micromachining and LIGA x-ray lithography methods) because of the greater number of layers possible. He adds, "The other methods are more time consuming and costly."
A patented, patterned insulation material provides a removable template for deposition of sacrificial material on a substrate. Blanket electrodeposition puts a metal coating over this material that is then planarized flat via lapping or polishing. The process is repeated for the subsequent layers building up the device. Chemical etching the final stack removes the sacrificial material.
The EFAB process can lay down layers from 2-10 microns thick with a total stack height up to 500 microns-not the 15-20 micron height limit of the other methods, says Vandelli. Because 3D CAD-based process software creates the device and its required layers, reproducing any shape, the design engineer doesn't have to be an expert in the technique nor design to process-specific characteristics.